Backup stock HTC Desire ROM with Unrevoked I want to play with different ROM's for HTC Desire (which is still under warranty). Based on my understanding, in order to keep the warranty and still play with custom ROM's, the following steps are required.


Root the Phone with Unrevoked Method
Take a backup of the stock ROM
Restore a custom ROM
And when warranty is required restore the stock ROM from backup


Am I going in the correct direction?. If yes where can I find the guides to perform all of the above mentioned steps.

*NOTE: I don't want to lose the warranty of the phone. I know it will get void once I root it but then there should be options to unroot the device and get it back to factory settings. *
If you root or install a custom ROM you void your warranty.  It doesn't matter if you undo it.  You might be less likely to be caught, but that depends on the carrier/manufacturer.  And if you're running a custom ROM and your phone breaks, you will often not be able to restore the backup (depending on how it broke).  If you want to keep your warranty, don't do anything that is against its terms.