Solved: How to hard reset O2 XDA Star: Press and hold the TALK and END buttons, and...

Resetting Your Device

Soft reset
Occasionally, you may need to reset your device. A soft (or normal) reset of your device clears all active program memory and shuts down all active programs. This can be useful when your device is running slower than normal, or a program is not performing properly. A soft reset is also necessary after the installation of some programs. If a soft reset is performed when programs are running, unsaved work will be lost.
To perform a soft reset
Remove the back cover and then with the stylus, press the RESET button found at the left side of your device. Your device restarts and displays the Today screen.

Hard reset Soft reset

Hard reset
You can also perform a hard reset (also known as a full reset). A hard reset should be performed only if a normal reset does not solve a system problem. After a hard reset, the device is restored to its default settings -‑ the way it was when you first purchased it and turned it on. Any programs you installed, data you entered, and settings you customized on your device will be lost. Only Windows Mobile® software and other pre-installed programs will remain.

To perform a hard reset

1. Press and hold the TALK and END buttons, and at the same time, use the stylus to press the RESET button at the left side of your device.
2. Release the stylus, but continue pressing the TALK and END buttons until you see the following message on the screen:

Hard reset Soft reset

3. Release the TALK and END buttons, and then press ENTER on your device.
Warning! Your device will be set back to factory default settings. Please ensure any additional installed programs and/or user data have been backed up before a hard reset is performed.
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.

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.
1. Tap Start > Settings > System tab > Clear Storage.
2. Enter “1234” then tap Yes.