I don't know which Operating System you are using, but try to boot using the CD disk supplied with the machine, Not just F8 on Start up. See what results messages you receive and post the results here. I think you might have a currupted or defective Hard Disk drive.
PS I'm a Fujitsu Drive user - you might need to access their website if you can get the PC booted and try out their drive diagnostics.
This Might be worth a go
Fujitsu | MHW2080AT | Drivers & Software
How much RAM - SP status Etc.
CAT III