H Resetting the phone

Don't do anything until you have backed up everything you need and have the BT install cabs if you want to get all your services back!
Contacts in your SIM don't get deleted but those in your phone memory will.
You will lose all Emails, photos, texts, ring tones etc unless they are on a memory card
You will lose the shortcuts so make a note of this website http://www.neilmorgan.co.uk/btbbanywhere
If you don't reload the BT software you will also lose the VOIP and Snap & Send facilities

Now for the reset

Make sure you aren't reading this on your phone!!!!

Switch the phone off

Hold down both soft keys and press the power button for less than 3 seconds

When a black screen appears asking for confirmation press the green telephone button

Follow the prompts

If you have the BT install files you will have full instructions there to load that software

And here's  a picture version

If you just cannot get it to reset using the method above then there is another way that does almost the same thing

CLEAR STORAGE, enter 1234 in the box, the handset will reset.