|When you put in the XP CD and it boots off the cd, the XP setup files copy across, and at the 1st screen, you should be able to choose Repair. Press r, and this will start the Recovery Console. |
When you are in the recovery console, choose your Windows installation (You will see what I mean when you follow the instructions.)
When you are sitting at the command line(C:\>Windows), access your CDROM drive by typing the letter followed by a colon, eg "D:". It may also be E:, F:, or G:.
When you have changed to the CDROM drive, type the following:
expand pci.sy_ C:\pci.sys <enter>
copy pci.sys C:\windows\system32\drivers <enter>
If it asks to replace, confirm.
Then restart your computer. If it finds more files missing, you may need to replace them using the same procedure.
Please respond if this helped. :)