Had this message on a Windows XP computer this week.
Here’s the fix:

I actually hooked the drive up to a working computer via my USB drive adapter. I then put the XP Home disk into my CD drive. I copied the file NTLDR and NTDETECT.COM from the i386 directory on the CD to the root of the offending hard drive. That fixed it. Obviously when you do the file copy, it will ask you if you want to overwrite the existing files. I actually renamed the old ones to “NTLDR.OLD” and “NTDETECT.COM.OLD” before I did the copy so that I would have a backup… just in case.

In order to view the files NTLDR and NTDETECT.COM on the hard drive, you will have to first enable the options to “Show System Files” under Control Panel->Folder Options->View.

All the best - and happy Thanksgiving!