For some users, unrooting is required when the phone has to go back to the manufacturer for repair. If the handset develops a warranty fault (a crackling speaker, non-working camera and so on) it’s likely that the manufacturer will refuse to fix it under warranty if it can see that a custom ROM
has been installed. In order for a warranty claim to take place the phone will need to be returned to stock condition. Rooting isn’t illegal as the phone is yours to do what you want with, but most manufacturers won’t fix devices that are hacked as rooting can cause the phone to be unstable and therefore open it up to problems the manufacturer doesn’t cover.
Alternatively, should you ever decide to sell off your rooted phone it may be easier to do if it is set to its default state. Custom ROMs aren’t for everyone and a less technically skilled user may feel more comfortable with a standard feature set.
Unrooting can be a complex procedure with each model requiring a different approach. Here’s how we did it on our HTC Desire test model. If you own a different Android device we urge you to research the necessary steps beforehand.
Discover how to unroot your Android phone
If your hacking days are over and you wish to go back to basics, we’ll show you how
If unrooting is a temporary measure then backing up your current ROM is a perquisite. With Nandroid or ROM Manager it is possible to create a snapshot of your handset’s current state and restore it at a later date.
2: Download HTC Sync
Unrooting a Desire is done via RUU files supplied by HTC. These need the HTC sync drivers to work. Get them at http:// www.htc.com/uk/help/ . Select HTC Desire and click News & Download to display the link.
3: Desire ROM
The Desire ROM is required so it can be flashed to the handset. These are available from the XDA developers forum via shippedroms. com at http://goo.gl/9ohBZ . Download the ROM that matches your handset.
4: Run HTC Sync
With everything downloaded it’s now time to install HTC Sync. Once that is done run the program and connect the phone to the computer via USB. When the Connect to PC menu appears select Sync.
5: Run the RUU file
With the handset connected it’s time to locate the downloaded RUU file and run it. Follow the prompts and the stock ROM will be flashed to your device. Make sure that your phone has plenty of battery charge beforehand.
6: Reboot into stock
Once the flashing process has completed the phone should reboot back into HTC Sense. You’re now back to your old default ROM. If the handset doesn’t boot up and returns an error message reconnect the USB and run the RUU again.
7: A bit of checking
Once the stock ROM is on the device you can check whether the root access has disappeared. Install Terminal Emulator from the Market. Run it and enter “su”. If it says Permission Denied then you’re successfully root free.
8: Go back to your root
Should you re-root your phone, repeat the procedure that was used before. If you still have your backed-up custom ROM from step 1 you can use ROM Manager to flash it and get back to your previous rooted state.
9: Other devices
The previous eight steps worked for our HTC Desire but other models of Android will require different processes. Resources such as XDA Developers and theunlockr.com are great places to find alternative solutions.
10: Other options
One such solution is the Easy Rooting Toolkit. The thread at http://bit.ly/tUhQvM has a dedicated unrooting section. The only stipulation is that it shouldn’t be used if the device wasn’t rooted with this tool.
Source : Android Tips, Tricks, Apps and Hacks