http://www.google.com/search?hl=en&q...=Google+Search
a listing of how to format { erase } hard drive with or with out XP
{i think! didn't have time to read thru them - a appt soon will check back later}
if all important is saved /emailed -go for it
Normally the XP CD on booting /auto run ect - will ask you about reformatting or repairing or total reinstall.
unles compaq has some thing built in to stop that feature???