Format

Thanks to all who answred my question on my pc freezing I got great answred some said chean my fan but that didn’t work I know have 98 bad cluster here my promable when you format how do you partetion the disk and what all do you back up beside your personale files How do you back up the hardware system I haven’t seen a save to it I know I should get a tech. to do it but can’t afford it right now and I would really like to learn to format Thanks BJ