O2 XDA Mantle soft reset
To perform a soft reset
Use the stylus to press the RESET button found at the bottom of your device. Your device restarts and displays the Today screen.
O2 XDA Mantle hard reset
To perform a hard reset using device keys
1. Press and hold the left SOFT KEY and the right SOFT KEY, and at the
same time, use the stylus to press the RESET button at the bottom of
2. Release the stylus, but continue pressing the two SOFT KEYs until you
see the following message on the screen:
3. Release the two SOFT KEYs, and then press TALK button.
Warning! Your device will be set back to factory default settings. Ensure any
additional installed programs and/or user data have been backed up before
a hard reset is performed.
O2 XDA Mantle hard reset with clear storage
Another way of clearing the device storage and reset all settings back to factory default settings is to use the Clear Storage feature. You will lose all your data and files on the device storage when you use Clear Storage, so make sure to do a backup first.
Important If Encrypt files placed on storage cards is or was enabled before, then backup all files from the storage card before using Clear Storage, hard reset or updating the ROM system software. Otherwise you will no longer be able to access the encrypted files on the storage card. Use ActiveSync or Windows Mobile Device Center to transfer files between your storage card and computer. After the procedure, copy your files back to the storage card.
1. Tap Start > Settings > System tab > Clear Storage.
2. Enter “1234” then tap Yes.
You can select "Also format NAND Flash" if neccessary.