Hi Glyn, I'm a bit out of touch with this thing but you used to be able to get your hands on a bootable floppy with a dos scanner on it. This will help you get around the virus kicking in.
I'd have a quick search on the Symantec or McAfee site's for such an animal.
Another thing you could do is put another disk in the PC (I know I'm getting a bit more far fetched here but a lot of people have extra bits lying around ...) and boot from that and then scan the other disk. Once you've got your IDE settings and an OS installed on the second disk ... of course.
