Boot message..missing NTLDR ??

All of a sudden when booting up win2000, get message (missing NTLDR...continue yes or no). Hit (yes) and it boots up and runs ok, so whats this about and what is a fix??

Thx
k

 

http://www.buildorbuy.org/win2000ntldr.html

 

Thanks and I do appricate it, but thats a great article explaining the boot process and whats needed but since my puter is a dual boot with w98, i think i need a dissemination on how to extract/replace the damaged ntldr file thats already here in my C:\> partition.
I really don't understand why it works at all, maybe if the root ntldr file is damaged, it gives a message and then uses the cache file.

But again, Thanks.........