The fix is to repair the ntldr (the ntldr is the boot loader) and the ntdetect.com (the ntdetect.com is responsible for detecting basic hardware)

To do this fix you will need a Windows XP CD.

Stick the Windows XP CD in, and boot your computer from the CD (if you need help getting your computer to boot from the cd, check out this excellent tutorial, http://www.windowsnetworking.com/j_helmig/bootcd.htm ).

Once you have booted up, you will see a Blue Screen like this:

Hit R, To go into the Recovery Console. You will have to type in the Admin password (If you don’t recall setting a password for the Admin, try leaving it blank then hit enter, if you get an error, that means that there was a password. You will need this password to continue)

Once in the recovery console, type the following (note my CD Drive is letter D: so change this to whatever your CD Drive is and my Windows is on C: so change that drive to whatever your Windows is on):

copy D:/i386/ntldr C:
(then hit enter, if it asks you if you want to replace a file, say yes)

copy D:/i386/ntdetect.com C:
(then hit enter, if it asks you if you want to replace a file, say yes)

Next type: fixboot

Then type: fixmbr
When you see the message are you sure you want to write a new boot sector, say yes

Then Reboot.