Hi. Windows Xp will not start up on my girlfriends comp. It comes up with an error saying something along the lines of pci.sys file is corrupt or missing. It then says about inserting install/repair disk and pressing r. She brought the comp second hand and she received no disks with it. I've obtained my mothers Xp install disk. Will i be able to repair the problem with this disk or will i have to buy a new copy and re install it ? Any help would be greatly appreciated.