also on certain systems one of the F keys will restore factory settings..
My son-in-law bought an HP pc that threw a wobbly and went tilt, i gave him a right rollicking for buying a system with no restore discs. It sat on the floor for months until i had a fiddle with it, hit an F key cant remember which one, and up it booted in recovery mode , doh!!
Then read the intstruction book...and there it was ,to restore to factory settings use F ? key..lesson of the day 'read instruction books'... ok, so i still dont well it is a blokey thing