why does my compuetr keep saying disk error please insert system disk?

Sounds initially to be a disk fault and you may need a new one. However, you say you have to keep reinstalling XP. Does this install OK and are you then unable to boot on restart? If you dont mind losing all your data on the drive I would use your XP cd to reformat and repartition your drive and then try and install again. Also go into the bios and see if its reading your Hard drive ok

RM
August 2008

Sounds as though your hard disk may be on the way out. Before you buy a new one however just try reseating its connectors.

t
August 2008