Can you please state which operating system you had on the drive. If it was windows98 you should be able to boot from floppy and see if you can access the hard drive.
The best solution really, is to remove the hard drive and put it into another machine (maybe a friends) as a slave and see if windows explorer can access it. If you have bad sectors in just system file areas then it should be ok for recovering data.
What happens when you switch on exactly? what messages come up?