q6600 is the model number of the processor, not the computer.
So taking a bit of a guess here!
You should be able to start the restore process by tapping the F10 key as soon as you switch the computer on and following the onscreen instructions.
However, before doing this I'd suggest you create a set of recovery disks, then if there is ever a problem with your hard drive you can replace it and you've got the media to set the computer up from scratch, if you don't create the disks and the drive fails (out of warranty) then you'd have to buy recovery media.
you should be able to find the recovery media creation utility in Start > All Programs > System Recovery > Recovery Media Creator.... run this and just put DVDs in the drive as it requests them, you'll probably need 3 or 4..... once you've created the DVDs then recover the system back to factory settings by the method above.