i found this reply on another forum..hope it helps.
First you need to boot to the recovery console.
To boot to the recovery console follow these steps:
1. Insert the Windows XP CD-ROM into the CD-ROM drive, and then restart the computer. Click(or press any key) to select any options that are required to start the computer from the CD-ROM drive if you are prompted.
2. When the "Welcome to Setup" screen appears, press R to start the Recovery Console.
3. When prompted type "1" or if you have a dual-boot or multiple-boot computer, select the installation that you must access from the Recovery Console.
4. When you are prompted, type the Administrator password. If the administrator password is blank, just press ENTER.
5. Now you should be at the comman prompt and ready to repair the ntldr file!
Now all you need to do is enter the following commands(in order) and each command on a new line just like you see them here:
cd attrib -c ntldr
Your computer should now reboot, and everything "should" work!