Restoring an Android device to stock is one of the first things potential root users wonder about: “If I root it, can I return it to the way it was?” There are several ways to do this, but I’m going to look at a ROM Update Utility (RUU) today. In the State of Root guide, there are a couple of places where you can grab an executable RUU for your HTC phone, but we’ve never actually had a full walkthrough of using an RUU on the site.
The first step to restore an HTC Android device to stock is downloading an executable RUU from a provider like shipped-roms.com. You’ll need to know your device’s code name, which is generally not the name you know the phone by. For example, the HTC EVO 4G is known as the Supersonic, the EVO 3D is the Shooter, and the EVO 4G LTE is known as the Jewel.
If you don’t know the code name of your device, you’ll need to Google or Wiki it. Usually a Wikipedia page on the device will contain the code name.
Also, make sure you get an executable version of the RUU you’re looking for if you want to be able to run it from Windows. Most of the zip versions contain the right files, but not the application to push the correct files to your device.
Once you’ve got the right version for your phone and carrier, it’s time to run it. You can watch the nine minute video I’ve done if you want to see what restoration of my wife’s old HTC EVO 4G looked like.
After it’s done, your phone should be like it was fresh from the box. The pictures and some junk data may be left on the SD card, so make sure to wipe that if you’re selling the device to someone.
If you get a security error when restoring, most likely you need to re-lock the bootloader before running the RUU.
One thing to keep in mind is that this returns it to a factory fresh state. This means once you start running it, your recovery and any root things you’ve done will be gone, so don’t expect to be able to boot into a custom recovery and undo an RUU. You can re-unlock, install a recovery, and pull data off the SD card, but it’s a chore.