I have a dual boot system with win2000 and FC-3. I was installing some software and playing around with the bootloader.
After some time when i rebooted the system and tried to boot in win2000 it gave me the message saying "NTLDR is missing , press ctrl+alt+del to restart".
The problem with the booting in win2000 is caused because of "ntldr, ntdetect.com and boot.ini" files.
What i did to rectify the problem is booted in FC-3 and copied file boot.ini from win partition to a floppy and downloaded files 'ntdetect.com' and 'ntldr' from the internet and copied to the same floppy.
After that i rebooted the system with the floppy and it worked, i found that the 'ntldr' file is renamed as 'ntldv'. I renamed that file to 'ntldr' and rebooted again to win.
And it worked.
The "NTLDR is missing" error can also be caused because of certain changes in hardware configuration like having a floppy in floppy drive while booting the system.