Develop Reference

INSTALL_FAILED_USER_RESTRICTED : android studio using redmi 4 device

Got this freaky error
Installation failed with message Failed to finalize session : INSTALL_FAILED_USER_RESTRICTED: Install canceled by user.
It is possible that this issue is resolved by uninstalling an existing version of the `apk` if it is present, and then re-installing.
WARNING: Uninstalling will remove the application data!
Do you want to uninstall the existing application?
When trying to run the apk in my redmi 4 MIUI 8.5.4.0
OEM unlocking enabled
Solution Tried
MIUI optimization turned off
USB debugging turned on
Verify apps over USB turned on
NOTE: while turning on install via USB a pop up saying The device is temporarily restricted

Steps for MIUI 9 and Above:
Settings -> Additional Settings -> Developer options ->
Turn off "MIUI optimization" and Restart
Turn On "USB Debugging"
Turn On "Install via USB"
MTP(Media Transfer Protocol) is the default mode.
Works even in MTP in some cases
Set USB Configuration to Charging

In your mobile device,make sure you have enabled the following buttons.
Settings > Additional Settings > Developer options
Install via USB
USB Debugging (Security settings)

The device is temporarily restricted error appears in MIUI 8.5. To resolve the error you need to make WIFI off and make mobile data on and then enable the option “Install via USB” under "Developer Options" in "Settings". it will work for you.

For me none of the above solutions worked. Instead i do following steps that solved the issue :
Developer Options > Mi Unlock Status > Add account and device. (A success message will appear)
Turn on USB Debugging.
Turn on Install via USB.
Note : This is checked on Redmi MIUI Global 8.5 version.
This solution will specifically solve the issue if you have recently logged out of Mi account & again logged in.
Hope it may help someone.

In my case, I pressed Deny unfortunately during first time installation. So I was getting INSTALL_FAILED_USER_RESTRICTED.
You can get modify this permission for app under permissions.
Settings->Permissions->Install via USB->{Your App}
You should have enabled below options too.
Settings->Additional Settings->Privacy->Unknown Sources
Settings->Additional Settings->Developer Options->Install via USB

Settings->Additional Settings->Developer Options
1) Turn ON Developer Options
2) Turn ON USB Debugging
3) Turn OFF MIUI optimization
4) Turn ON Install via USB

For MIUI 12:
Developer options (On)
USB debugging (On)
Install via USB (On).
Allowed "Android System" to install from Unknown apps. (Try "More/Show system" if you can't see it in the list.)
This worked for me but got an android security warning.

For MIUI 9.6 works:
1. Become a developer: Settings >> About phone >> MIUI version tap 7 times.
2. Again Settings >> Additional settings >> Developer options (turn on) >> USB debugging (turn on) >> Install via USB (turn on).
3. You will be asked for permission through your MI account. Confirm permission.
4. Note: During the installation of the application, your device will give you 7 seconds to confirm the installation. Don't miss it!

For MIUI global 13 and above to turn off MIUI optimization
go to the developer option
go down where button one was "Reset to default values"
press it 5 times or more,
then the turn-off MIUI optimization is visible

Xiaomi MIUI.
Options - Permissions - Install via USB (not the same item in Developers options!)
then uncheck your disabled app

You have to enable developer mode then
settings -> additional settings ->
USB debugging: sets ON
Install via USB: sets ON (to do this you have to insert a sim card otherwise you'll not be
able to enable it)
[![enter image description here][1]][1]
[![enter image description here][2]][2]

Turn off MIUI optimization from Developer options
install the app
turn it back on.
next installs of this apk(and its updates) wont give this error anymore.

Reference
The same trouble with the same device has been here.
So, it's Xiaomi trouble, and here is a solution to this problem:
Go to the "Security" application and tap "Options" at top right
corner
Scroll down to "Feature Settings" group, and look for "Permissions"
At there switch off "Install via USB" option, which manages the
installation of the apps via USB and doesn't allow it.
On Latest Redmi Device:
Settings > Additional Settings > Developer Options > Developer options: Check the Install via USB option.

Just Disable Mock SD card optimization in the developer options
Turn off "Turn on MIUI optimization"
Mark force-closed apps
These Settings worked for me.Cheers!

If above answer didn't work for you as it didn't work for me on my Xiaomi Mi5.I tried to figure out the Core reason behind it and solve it. In MIUI, in order to change "Install via USB" option, you must be connected to the internet and signed in your Mi account. Due to some reason, requests from out of the China servers are getting rejected, so I connected to one open China VPN and tried again to enable 'Install via USB' and I got success. For detailed solution and VPN details, see this useful Youtube video: https://youtu.be/MeKUJlD-Ke4

For me, this works only
Steps for MIUI 9 and Above:
Settings -> Additional Settings -> Developer options ->
Turn off "MIUI optimization" and Restart
Turn On "USB Debugging"
Turn On "Install via USB"
Set USB Configuration to Charging
MTP(Media Transfer Protocol) is the default mode.
Works even in MTP in some cases

Failure [INSTALL_FAILED_USER_RESTRICTED: Install canceled by user]:
Go to Settings->Additional Settings->Developer options->Developer Option(Need to enable)->USB debugging(Need to enable)->Install via USB (Need to enable)->USB debugging (Security settings)(Need to enable)
Perfectly working in the above steps.
Enjoy your coding...

To turn on "Install via USB" and "USB Debugging(Security changes)" need to sign in to xiaomi account then these 2 can be turned on and work with redmi as developer
Note:When turning on USB Debugging(Security changes) few security alerts will be poped up all need to be accepted to work on developer mode

How to Fix Install Failed User Restricted Failure in Android Studio -
For Xiaomi Redmi Note 4X (100% worked for me)
Settings=>Additional settings=>Developer Options
Mock SD card optimization = OFF
USB debugging = ON
Install via USB = ON
USB debugging (Security settings) = ON
Verify apps over USB = ON
Force-closed apps = ON
Turn on MIUI optimization = OFF

With Xiaomi Redmi note 8 pro (MIUI 10.4.4), Android 9 -
While connecting to Vysor (2.1.2) from Windows PC (via USB cable), received the error message:
"Error installing APK: Failure [INSTALL_FAILED_USER_RESTRICTED]"
even after turning "USB Debugging" On.
So the following settings were required -
Developer options (On)
USB debugging (On)
Install via USB (On)
Leave the following,
Turn on MIUI optimization (On)
Verify apps over USB (On)

Turn on usb debugging
Turn on Install via USB :->
While turning on it asks for mi account sign in you can get instant otp vis sms service to sign in quickly.
Turn off MIUI optimization.

Updated MIUI 12:
I have to turn on "OEM unlocking" beside other settings.
(I don't need to change "Mi Unlock status"

If it's still not working try adding android:exported="true" and upgrade your dependencies

It's simple, in MIUI 9.x you need developer settings ON and then
Settings -> (system & device section) Additional Settings -> Developer options
(Debugging section)
Turn On "USB Debugging"
Turn On "Install via USB"
Then in Android select Runb app and choose your Xiaome phone
EDIT: you will also need allow installation from unknown sources

what worked for me
goto Settings -> Additional Settings -> Developer options -> Revoke USB Debugging Authorizations.
Kill adb.exe in the taskmanager (CTRL + SHIFT + ESCAPE)
Install again, watch for popups (accept RSA signature and install)
Everything will work now

first, check your USB debussing options all mandatory should be enabled.
then uninstall the application from the device and then try to reinstall again.
this works for me.

Another possible reason in case if you have accidentally denied installing specific application - remove it from blacklisted.
It is under Security > Install via USB.
Note: You may not simply find it from Security. Instead search for "USB" from Settings search and look or that option in Security.
If your app is there - simply remove from the list. If not - then it's some other problem.

If you are still facing INSTALL_FAILED_USER_RESTRICTED issue try this
this methods works for me in miui 13
Setting->Permissions->Install via USB->untick your app

for more detail video
1) Turn ON Developer Options
2) Turn ON USB Debugging
3) Turn OFF MIUI optimization
4) Turn ON Install via USB
youtube video for more visual understanding

For me only installing from Google drive worked.

I am getting error when i install my Android app in device Redmi 3s prime, and it is working on genymotion emulator

I'm having this error:
$ adb push
F:\skylixwork\CollagePhoto\app\build\outputs\apk\app-debug.apk
/data/local/tmp/com.collagephoto java.io.IOException: An existing
connection was forcibly closed by the remote host
Error while
Installing APK
Installation failed with message INSTALL_CANCELED_BY_USER.
It is possible that this issue is resolved by uninstalling an existing version of the apk if it is present, and then re-installing.
WARNING: Uninstalling will remove the application data!
Do you want to uninstall the existing application?

Works !
enable developer mode - In your phone, go to Settings, About phone and click on MIUI version 7 times. You’ll see a pop up which says you are a developer now.
Go back to Settings, Additional settings, Developer options and enable USB Debugging.
Connect your phone to your PC/Mac and on the phone authorize your computer
go back to Developer options, scroll down to find Turn on MIUI optimization and disable it. Your phone will be rebooted
I solved my issue this way.

I found the answer for my question.
solution :- (1)
enable developer mode - In your phone, go to Settings, About phone and click on MIUI version 7 times. You’ll see a pop up which says you are a developer now.
Go back to Settings, Additional settings, Developer options and enable USB Debugging.
Connect your phone to your PC/Mac and on the phone authorize your computer
go back to Developer options, scroll down to find Turn on MIUI optimization and disable it. Your phone will be rebooted
solution :- (2)
enable developer mode - In your phone, go to Settings, About phone and click on MIUI version 7 times. You’ll see a pop up which says you are a developer now.
Go back to Settings, Additional settings, Developer options and enable USB Debugging.
Connect your phone to your PC/Mac and on the phone authorize your computer.
go back to Developer options, scroll down to find Install via USB: and just turn on it.

I'm using xiaomi redmi note 4x and after Turning on install via USB, Turning off MIUI optimization is the main objective from developer option to run app via USB! This works for me

I will suggest to check update of adb version. Aslo check the your Run Apps on a Hardware Device
For more information refer this solution ADB connection
Try above solutions. hope it will work

1 adb devices check your device is ok
2 reboot your devices
3 adb install -r F:\skylixwork\CollagePhoto\app\build\outputs\apk\app-debug.apk

LG G4 not recognised by Android Studio

I just got the LG G4 phone, turned on developer options mode, tried running an app from Android Studio but it can't recognise my phone. I even tried switching from MTP to PTP but still it's not recognised. I tried a lot of resources out there, still nothing. Please can anyone help?

So i restarted my device, and switched USB options from MTP to PTP. and for some reason it worked. I dont know why. Thanks for answers above, much appreciated

Had the same problem and tried everything mentioned above with no success. What ended up working for me was downloading the LG Android USB device Drivers which can be found here: http://www.mylgphones.com/lg-android-usb-device-drivers
The latest drivers didn't work for me so I downloaded the second latest and voila! It worked! Hope this helps.

None of the answers here worked for me until I turned on USB debugging mode in Developer Options.
For completeness, the steps are:
Go to Settings > About phone > Software info
Tap "Build number" 7 times until it says that you're a developer
Go back to Settings, and tap on the new "Developer options" item (second last in the menu)
Enable "USB debugging"
Plug in your phone
Change from MTP to PTP mode
Allow the computer to access your phone (there should be two messages - one of them should be for the RSA key fingerprint)
And that should do it. Run adb devices and you should see the phone.

switched USB options from MTP to PTP. when you try to switch it will ask to install drivers then clicked on Install ....now you can debug your app on device

Check your phone, it will ask to install driver on PC. Afterwards android studio will see your phone

Here's what I had to do:
Install the LG Mobile Drivers: http://lg.com/us/lgeai/drivers (latest at the time of writing: here)
Disable USB debugging if currently enabled (this was key for me)
Enable USB debugging
Plug into computer
Allow USB debugging when prompted (will show RSA fingerprint, check "always allow").
Trust the computer when prompted (allow access)
Switch to PTP
Install USB driver when prompted
Wait for the driver to finish installing on your PC
adb devices should show your phone now. If you don't get some of the prompts above, try unplugging and re-plugging your device. Also try different USB ports on your machine.

I had same problem. I was checking Developer Options after plugging USB cable, the USB Debugging option was unchecked and grayed out while cable plugged. I unplugged USB cable, checked USB Debugging option and plugged USB cable again, it worked.

I had the same problem with an LGL58VL test handset. Other (non-LG) handsets worked without problem. Installing the Google USB driver didn't help (Windows said "installed driver (LGE Android Net MTP Device) is already up to date".
Here's what worked for me
WINDOWS: Download and install LG driver on Windows:
http://lg.com/us/lgeai/drivers
HANDSET: Enable developer mode:
Settings > Software Info > Tab "Build number" 7 times
HANDSET:
Settings > Developer options >
Enable USB debugging => YES
Select USB Configuration => MTP
WINDOWS:
Plug in handset. "Action" => Nothing
HANDSET: Accept RSA key
WINDOWS: Android Studio > Tools > Connection Assistant >
Verify handset device is listed and available for debugging
ALSO: sometimes, after I enabled other test devices, the "Enable USB Debugging" option for the handset became grayed out.
WORKAROUND (Handset):
Settings > Developer Options >
Turn Developer Options OFF (slider at the top)
Turn Developer Options back ON
I was now able to hold down "USB Debugging" and slide it back to "ON"

You have to activate developer mode for your device.

Try tap "adb devices" in shell window( or command window)
1) if still nothing displayed, it must be not related to studio, please check whether drivers is properly installed or register in system(Different system has different methods).
2) if displayed like "0b63d5xxxxxxxxxx device", it should be studio's problem, check view option or reinstall android studio.

How to fix: Error device not found with ADB.exe

In cmd when I try to do the command:
adb shell
it shows device not found error. Can someone help me please. It'll be appreciated.

Don't forget to go to your device and enable Settings->Developer Options->USB debugging.

Try any of the following solutions. I get errors with adb every now and then.
And one of the following always works.
Solution 1
Open command prompt as administrator and enter
adb kill-server
adb start-server
Solution 2
Install drivers for your phone if you're not testing on emulator.
Solution 3
Open android sdk manager and install "Google USB Driver" from extras folder. (attached screenshot)
Android SDK Google USB Driver missing
Solution 4
Go to settings > Developer Options > Enable USB Debugging.
(If you don't see Developer Options, Go to Settings > About Phone > Keep tapping "Build number" until it says "You're a developer!"
Enable USB Debugging

It depends on windows system but usually:
you go to system properties
look at hardware devices
Right click on the yellow (has to be yellow if it's driver problem) icon representing your mobile device
select property
Then go on the driver tab
select update driver
choose the bottom selection find on local computer
then choose manually
From the windows opened look for driver disk the bottom right button
Choose the driver from the folder <sdk>\extras\google\usb_driver\i386 (or amd64 for and).
Remember to uncheck the show only compatible hardware.
Then choose the driver
When windows warn your about possible incompatibility go on.
For my mobile it works, but depend on your mobile if it work or not.
Hope this help, bye.

If you installed Eclipse have Android SDK, go to DDMS. If the list device display "?????????"
you do adb kill-server and then adb start-server.
Please make sure you install USB driver and enable debug mode.

Another issue here is that you likely need to turn off "connect as media device" to be able to connect with adb.

For me, I have to Revoke USB debugging authorizations in Developer Options. Here is the steps:
Turn off USB Debugging,
Revoke USB debugging authorizations,
Plug the cable back in,
Turn on USB Debugging

I solved:
Just turn off USB debugging and re-enable debugging it immediately

On my G2 I had to select PTP instead of MTP mode to get the connection to work.

I had this problem suddenly crop up in Windows 7 with my Nexus One - somehow the USB drivers had been uninstalled. I ran android-sdk/SDK Manager.exe, checked Extras/Google USB Driver and installed it. Then I unplugged the phone and plugged it back in, and ran "adb devices" to confirm the phone was attached.
This doesn't work for all phones, just the ones listed here:
http://developer.android.com/sdk/win-usb.html

Developer options
USB Debug
if you can not see developer option, go to about. build version and click build version until developer options in unlock.

Try changing USB port.
Try restarting adb server.

I have a Droid 3 (Verizon). I went to Motorola here and found the driver for the device 'Motorola ADB Interface' which was showing in device manager. It's kind of a big download for just the driver, but during installation it found it and installed correctly.

I switched to a different USB port and it suddenly got recognized...

How about:
Settings -> System -> Developer options -> Debugging -> turn on toggle for Wireless ADB debugging
or:
Revoke USB debugging authorizations
and try from the scratch.

Just wanted to provide a simple answer here. I am just messing with an old Android device for the first time doing these root and unlock procedures. I received an error like this one when an adb push "..." "/sdcard/" command failed, and the key was that my device was in the bootloader screen. Booting to recovery then allowed me copy over the file(s), and I presume the normal OS would as well.

This worked for me, my AVG anti virus was deleting my adb.exe file. If you have AVG try:
1) opening the program
2) go to options
3) go to the virus vault and click on it
4) find your adb program, click on it, and press RESTORE at the bottom
This will move the file back to its original place.
However, unless you turn off the AVG it will delete the file again.
After this android studio located the file. Good luck.

I found my solution from this similar thread by enabling USB tethering on my LG G6 (requires data saver to be turned off)
Go to: Settings -> Tethering & networks -> switch on USB tethering

For completeness, I've just had a case here I had to change my USB cable. Guess the one I had was for charging only, accursed thing.

On my Sony Xperia XZ1 Compact on Oreo I had to switch USB mode to MIDI to get it working. Only after this my Windows recognised Android ADB, however it couldn't autoinstall driver. I opened Device Manager and installed the Google USB Driver for the ADB.

To solve this problem,
Add adb folder to your windows path (system veriable)
This solves the problem

In my case I needed to swap the ends of the cable connecting my device to the computer...

Device not detected in Eclipse when connected with USB cable

I want to run my Android project on a device.
My device is not detected in Eclipse when I connect it with a USB cable.
I restarted Eclipse and I have checked that USB debugging is on, on the device.
Can anybody tell me what the problem is and how to resolve it?

Before starting, Make sure that USB DEBUGGING IS ENABLED in your phone settings !!!
1) BASIC STEP - Plug in device via USB, then go to device page in Android developers blog. There you can find necessary information regarding adding USB vendor ids. Add your device specific ids, and restart eclipse if needed.
2)If you were able to see the device connected(using command: 'adb devices'
) earlier, but not anymore, then just try restarting ADB. (you can use the commands: 'adb kill-server' followed by 'adb start-server'. adb commands need to be executed from platform tools folder in the Android SDK, if you havent exported it).
3)If neither of them works out and you are on windows machine,
then check the installed usb drivers are correct. If not install proper drivers
Please find more information on how to install/update drivers in http://developer.android.com/tools/extras/oem-usb.html
If this also is not working, try installing Universal ADB windows driver https://plus.google.com/103583939320326217147/posts/BQ5iYJEaaEH
4)You may also try increasing the timeout time
Go to preferences-> android->DDMS in eclipse, then try increasing 'ADB connection timeout(ms)' value
Update based on newer answers:
5)Run > Run Configurations > Target. Please make sure, the option "Always prompt to pick device" is enabled.
Special case: Windows 8 and Nexus 10 (from this question: ADB No Devices Found)
Windows 8 wouldn't recognize my Nexus 10 device. Fixed by Setting the
transfer mode to Camera (PTP) through the settings dialogue on the
device.
Settings > Storage > Menu > USB Computer connection to "Camera (PTP)"

I solve this problem by updating PC portable device drivers:
Go to : Settings -> Applications -> Development to enable USB debugging
Plug in device USB
Desktop "My Computer" right click -> "Manager"
Choose "Device Manager"
Portable Device
right click on your device -> "Update Driver software" -> Search automatically (wait about 3-5min, )
Done

Restarting the adb server, Eclipse, and device did the trick for me.
C:\Android\android-sdk\platform-tools>adb kill-server
C:\Android\android-sdk\platform-tools>adb start-server
* daemon not running. starting it now on port 5037 *
* daemon started successfully *
I had the same problem as mentioned on this question.

I had similar problem, drivers was okey, but Eclipse did show me the device in Run > Run Configurations > Target tab. But I checked the option "Always prompt to pick device". And then running the application from Eclipse the prompt window finally showed my device.

After a long and frustrating search, finally I made my Micromax Funbook p362 to connect with eclipse and made it to suit for development.
*Installed Moborobo (All in one Android smart phone management tool).
*Perform stop -server / start -server using ADB.
*Reboot the device.
*Restart the eclipse.
*Device got detected.(Eclipse - list of adb devices)

In addition to the steps provided by #asfsafgsf (above), make sure to re-enable your phone's developer modes/functions. For my Motorola Atrix:
settings>applications>Unknown Sources: allow 3rd party apps
settings>applications>Development: to enable USB debugging, mock locations, and disable phone sleep
A note on developer modes
USB Debugging is the main mode you will need for running apps through eclipse when your phone is connected via usb (obviously). Disable phone sleep is also handy for self-explanatory reasons.
Allowing 3rd party app sources allows you to beta test your app on a larger-scale. With this, you can host your own apk and instruct your beta-testers to download it (prior to releasing it to the Google Play storefront). More specifically, 3rd party support allows the installation of android package files that don't contain a google approved signature (required for play store hosting). With 3rd party apps enabled, a handset will be able to run packages regardless of their source. You should also be able to receive an APK via bluetooth and install it in this mode.

You can also list all currently connected devices by running the following command:
adb devices

Go to http://developer.android.com/tools/extras/oem-usb.html#InstallingDriver and follow the steps on the android website but on browsing for the USB folder don't use the directory specified -> ((sdk)\extras\google\usb_driver). (sdk) just means your sdk location.
Your phone should have the correct driver and it can be accessed when you plug it in and go to the CD Driver in My Computer, in my case it's G:\drivers\adb_driver. Use this directory instead and it should work. (It may be differ with devices).

One possible reason is to check Android SDK Manager and install Google USB Driver in Extras folder if you have not installed it.
Following the steps here: http://developer.android.com/sdk/oem-usb.html#InstallingDriver allowed Eclipse to display the device.

Do following steps to detect your device in eclipse : -
On Mobile Side:- For Connect USB sync, your Android device needs to have USB Debugging enabled.
To enable Android USB Debugging Mode do following steps :-
Android 2.x - 3.x devices:
Go to Settings > Application > Development > USB Debugging.
Android 4.x devices:
Go to Settings > Developer Options > USB Debugging.
For devices running Android 4.2.2 or later, you may need to unlock Developer Options before it is available within the Menu:
Go to Android home screen.
Pull down the notification bar.
Tap "Settings"
Tap "About Device"
Tap on the "Build Number" button about 7 times.
Developer Mode should now be unlocked and available in Settings >
More > Developer Options or in Settings > Developer Options
On PC side
Connect your device to the PC with USB cable.
Download Google USB Driver
Extract/Unzip “latest_usb_driver_windows.zip” file on your computer
(using 7-zip free software, preferably)
Open device manager on your PC
Windows 7 & 8 users → search for
Device Manager from Start (or Start screen) and click to open.
Windows XP users → Google it
You will see list of all devices attached to your computer in the
device manager. Just find your device (it’ll most probably
be in the Other devices list with a yellow exclamation mark by the
name of ADB devices), then Right-click on it and select Update
Driver Software.
Select “Browse my computer for driver software” in the next window
Now click the “Browse…” button and select the “usb_driver” folder
that we extracted in Step 3 from “latest_usb_driver_windows.zip”
file.
Do NOT select the zip file, select the folder where the
contents of the zip file are extracted. And keep the Include
subfolders box checked
During the installation (as a security check) Windows may ask your
permission to install the drivers, click “Install”
Once the installation is complete you’ll see a refreshed list of
devices on the Device manager screen showing your phone’s driver
installed successfully.
Now in eclipse do following steps to install your app in your device:-
Go to Run > Run Configurations > Target tab.
Check option "Always prompt to pick device". And then running the
application from Eclipse,the prompt window finally showed
your device.

Please check whether your device is shown in the Eclipse device tab in Window > Open Perspective. If its not shown there then you need to install drivers for the the device. Once the device is visible in the Devices tab then change the launch settings for manual target. Once you launch your app then it will allow you to choose from the real device or the virtual devices

If you have the following problem
Then you can so following to fix it
Note : You should enable USB debugging on your android device(It will be in developer option in System settings)

I had this problem. With my galaxy S2. So came here for advice, but couldn't find anything specific. Then I found this 'Kies' software on the Samsung site, under the section for my exact model of phone, under downloads, after clicking software.
It installed the right USB drivers as part of the process of installing Kies and so my phone instantly then became visible on eclipse.
The Kies version for Galaxy S2 (GT I1900) = http://www.samsung.com/uk/support/model/GT-I9100LKAXEU-downloads#
There are other versions of Kies for other android models of course.

(new) device not showing, Check List:
Developer Option ON
USB debugging ON
Try changing to USB Storage/MTP/PTP
if it installs Window driver and fails, there's your problem (verify in Windows Device Manager) fix it.

ok this is an old thread -
but I spent nearly two days and did not get anywhere
Here is what solved my problem
I had USB debugging enabled ( finding developer options itself was a pain - I think the 7 times tap from google is childish and just plain stupid - rant over )
However HTC syn manager , eclipse ADT and windows computer management were all unable to identify my device
My problem was my phone was set to ONLY USB Charge - this was the problem
In 'USB Computer connection' >> Choose the option USB Storage
Once you do this - PC will install drivers and your device will get detected by Eclipse as well as in 'Computer Management' under ''Android USB devices '
Now I still dont know a way to access ''USB Computer connection' but at that time I did get the option to change and t worked
For those ( like me earlier ) who dont know how to identify if 'Computer Management' shows their device look for 'Android USB devices '
If its present - then your device is being detected by your PC
Hope this helps some others
shankar

On a kitkat Google Nexus 7, I tired everything here, and did not succeed. The device did previously connect properly to this computer.
Then I hit settings - developer-options - Revoke USB debugging authorisations
and confirmed that I really did want to revoke them.
I unplugged and plugged the USB. The tablet beeped and asked if wanted to authorise the computer for debugging. I said "Yes" and everything worked again.

For me the problem is with Defective USB Cable. I have tried those above all answers. Nothing gives me any fix. But finally i came to know the problem is because of my usb cable while changing the usb cable. While connecting through the usb cable the phone is charging but the drivers are not installed. Some usb cable don't have the option for that. So while buying check it and buy.

Best approach is install PDA net(software) on both system as well as in android device. This software automatically installs global driver for all phones, provides easy connectivity to android device.
Follow these links to download
For system
http://pdanet.co/
For android device
https://play.google.com/store/apps/details?id=com.pdanet&hl=en

Here is my checklist in windows (not the device itself) when my device is not shown:
Make sure "USB debugging is turned in setting>Developer options.
Check status bar on your device. It tells you if your phone is connected as Media Device (MTP) or Send images (PTP). My device is only listed when PTP is selected.
Turn of windows firewall.
Turn of any proxy programs ran on whole windows ports.
And finally stop adb.exe from windows task manager and wait some seconds to restart automatically.