NTLDR or NTDETECT.COM Not Found.

If you get an error that NTLDR is not found during bootup,
If you have FAT32 partitions, it is much simpler than with NTFS.

Just boot with a Win98 floppy and copy the NTLDR or NTDETECT.COM files
from the i386 directory to the root of the C:\ drive.
For NTFS:

1. Insert and boot from your WindowsXP CD.
2. At the first R=Repair option, press the R key
3. Press the number that corresponds to the correct location for the installation of Windows you want to repair.
Typically this will be #1

4. Enter in the administrator password when requested

5. Enter in the following commands (X: is replaced by the actual drive letter that is assigned to the CD ROM drive.
COPY X:\i386\NTLDR C\:
COPY X:\i386\NTDETECT.COM C:\

6. Take out the CD ROM and type exit