Procedure last edited on 9/4/2012 (Thanks to sdrawkcab25 for help with various procedures herein) Due to major changes to the radios and bootloader since HTC Dev was introduced, this thread is now mostly applicable to those who went s-off back in the day and used the Unrevoked method to root and aquire s-off. Also, this is only written for those wanting to go back to full stock and s-on which is generally NOT recommended unless you are returning a phone and want no evidence of root activities. Note: Your SD card MUST be formatted to FAT32 before proceeding, if downgrading your radio for s-on and/or using option #1. The PB31IMG files will not be recognized otherwise. If you have yet to format, remember that formatting wipes the card. Be sure to copy/move your SD contents to a safe place (PC desktop) and replace after the formatting process. I will not go into the procedure in this thread as it is easily found with a Google search. 1.) Download the 2.2 (Froyo) factory rom: http://pvillecomp.com/wp/wp-content/uploads/Images/Froyo-Stock-recvery_PB31IMG.zip MD5: 31bb1611a0fa8197d447c0438426717e ** Once downloaded, rename zip file to PB31IMG.zip ** (MD5 verification is done to ensure the file you downloaded is complete and it's integrity is entirely intact. Skipping this verification is not advised. If you have questions about how to verify MD5, please see post #2 of this thread). 2.) Attach phone to PC with USB debugging on and in disk drive mode. 3.) Access the SD storage and drag the PB31IMG zip file (still fully zipped) from the desktop onto the root of the SD card (any open area, do not place into a folder). 4.) Swipe down notification bar on phone and change to charge only. 5.) Unplug phone from PC and turn off phone. 6.) Hold volume down while pressing power button to enter hboot. 7.) PB31IMG.zip should be automatically recognized in hboot. Press volume up to continue with update. Do NOT interrupt. 8.) When finished, reboot to stock 2.2 and verify the following information at Menu > Settings > About Phone: Android Version: 2.2 Baseband Version: 2.15.00.07.28 9.) Remove the PB31IMG.zip from the SD card because we are about to place another one on the card and we don't want to cause confusion with 2 files of the same name. You are now unrooted and on stock 2.2. Explanatory note: Ok, so the reason we went back to 2.2 is because it is still rootable using Unrevoked and because the 2.2 radio will allow the s-on file to be applied. So although it may seem odd at first glance, we now need to reroot using the original Unrevoked method, then apply the s-on file... 10.) Reroot using Unrevoked which can be found here: unrevoked3 recovery reflash tool, v3.32 This will root your phone and provide you with Clockwork recovery so we can flash the s-on file. 11.) You can now proceed to flash the s-on file by visiting public:forever [RootWiki] where you can download the required file. Scroll down to the section labled "Installation Instructions", you'll see it there. Move the file to the sdcard (leave zipped and no need to rename it), then access your clockwork recovery to install using the options...Install zip from sd card > Choose zip from sd card. Then locate and install. No wiping of any kind is required when flashing this file. 12.) You are now s-on but still rooted. So to remove root and get back to Gingerbread, acquire the following file (2.3.4 factory rom) and once again rename it to PB31IMG.zip, place on the sdcard and load from hboot (not recovery) using all the same steps you used above when downgrading to Froyo: http://www.mediafire.com/?1ovb6959r9qyg6w MD5: 4b7e23b052520978dcd100f008880f82 You are now unrooted, s-on and running Gingerbread 2.3.4. Because there were some later updates to the bootloader, you may still be prompted for an OTA update. Either accept it or just keep denying the update until the phone is brought in for return. It won't matter because you're still on stock with a clean bootloader.