Before you Start
1) You must have rooted your Noir A10 using this tutorial. If you used another method, then this trick may or may not work for you.
2) You might brick your device while rooting. So follow the instructions carefully.
3) Make sure everything is in order and that your device is charged.
How to Unroot
1) On your device, go to Settings > Development and enable USB Debugging.
2) Connect Noir A10 to your PC. Install device drivers using PDANet (If they are not already installed).
http://www.droidiser.com/2012/11/how-to-install-drivers-for-any-android.html
3) Download the following package and unzip it.
OR
https://dl.dropbox.com/u/93588460/QMobileNoirA10RootPackage.zip
4) Inside the package, open the RunMe.bat file.
5) You’ll see a command prompt appear on your screen.
6) Type “X” (Unroot) and press Enter.
7) Now keep on following the on-screen instructions until the process completes.
Congratulations, your device has been successfully unrooted and you no longer have the superuser permissions. You won’t see the superuser app as well.
(Note: Your device may reboot during this process).
QMobile Noir A10 