HP Pavilion

Hello,

I'm trying to help a friend out she has a HP Pavilion. The only screen that will come up says (Invalid system disk or disk I/O error Press any key to restart) continuing taking you back to that same screen. When you push F1 it will enter in the set up screen. ???

I'm not able to get to a screen to delete a partition and make a new on with the XP disk?

Please Help!!