do you dual boot?
try a repair option
pop in NT Setup Disk #1 and reboot. Put in #2 when prompted. When setup asks what you would like to do, press the "R" key which stands for repair. You should then be faced with a screen with these options:
Inspect registry files
Inspect startup environment
Verify Windows NT system files
Inspect boot sector
Continue (perform selected tasks)
Make sure that "Inspect boot sector" is the only choice with an "X" in the box, and chose continue. After a while, you're faced with a screen saying this:
Setup has completed repairs.
If there is a floppy in drive A:, remove it.
Press Enter to restart your computer.