This error
can occur when the partition containing the operating system does not
contain the boot files. This results in windows not loading. The first
area to check is that the hard drives are plugged in correctly and that
the cables are not loose. When these have been checked if all ok then
place your windows XP CD into the drive and boot from it.
Press F10 then
R and Select the recovery console. Press C to start recovery console.
Copy the NTLDR file from the Windows XP CD-ROM to the root of your
system partition by using the following commands, pressing ENTER after
each command:
1. Type cd\ to go to the root of drive C
2. Type the letter of the CD-ROM drive
3. Type cd i386 to change into the right directory
4. Type Copy ntldr c:
5. Type Exit