To make things clear:
Is it 80 Gig drive as it is described here ?
Is it 1250 or 250 meg partition?
If you created any partition after this incident, then there is no practical way to recover your drive except restoring the backups from DVDs (ghost, drive imaging...).
You can try this:
DISABLE the drive in BIOS and then try booting (and install) from windows setup CD. You will not have an option of repairing the current windows installation, (fresh install only) but it might jump-start your MBR.
If you are wondering if I've lost it, know this: Windows setup program accesses chipset directly and detects drive presence, ignoring BIOS settings. For some reason, if the drive is disabled in BIOS, it will not give you an option of repairing the installation. Don't forget to enable the drive after 1st reboot. Hopefully you will not have to delete the partitions and therefor loose all data on your drive.