Im looking at restoring my laptop to how it was when I first got it, at the moment its kinda slugish. However every forum I seem to go on tells me to press F8, when my system boots up, to take me to 'Advanced Boot Options', and then  selet 'Repair your Computer'. But the probelem is that isn't there. All I have is :

Safe Mode

Safe Mode with Networking

Safe Mode with Command Prompt

Enable Boot Logging

Enable low-resolution video (640x480)

Last Known Good Configuaration (advanced)

Directory Services Restore Mode

Debugging Mode

Disable automatic restart on system failure

Disable Driver Signature Enforcement

Start Windows Normally

Any ideas what I have to select, and what do I have to do to restore my computer. (Oh and by the way I've got Vista not XP if that makes any difference. Ive also been on the Dell support website, but that also tells me to select 'Repair your computer')