Please can anyone help me out, I got a PC, that the previous owner infected with a trojan that kicked off 2 days after he left the country...Long story...Anyway I'm in a position where:

Boot disks, (tried XP & Win2K) fail, as I get a blue screen boot sector stop while trying to install.

Hiren boot cd can detect no HD, (I've tried 3 different HD's...) They're fine in Bios.

Removed the HD battery to reset everything, same problems as above.

All the microsoft web suggests is antivirus s/w, which isn't any good that I can see, because as far as the PC's concerned I have no HD.

Any advice, excluding "get a hammer, a small blowtorch, some mentos & a bottle of coke..." (as I'm getting close to trying this myself), would be really appreciated.