Computer keeps Rebooting / Ntdetect failed.

A friend just ask me for help with her laptop. It keeps on rebooting. And I mean that it doesnt even shows the windows loading. It just keeps on repeating the bios screen.

And then when I look carefully, just before it reboots, I saw for less than a second, the word Ntdetect failed. I googled it and found a solution. Simple. Took me less than 5 minutes to solve it.

Run XP repair.
Type in:
COPY X:\i386\NTLDR C\:
COPY X:\i386\NTDETECT.COM C:\
where X is the drive letter for your CD drive.
Remove the CD and type exit.