Whilst surfing, my computer froze, with the HDD light constantly lit. Eventually, could only regain control by switching off. On restart it refused to recognise the HDD. Opening BIOS setup showed a blank where the HDD model and serial would be. Using a bootdisk to try fdisk/mbr to repair the mbr, gave a msg of no fixed disks. When I put the HDD in an external USB box (SafeCom), and another HDD in the computer (still with XP Home, but no AV), the partitions of the remote drive were visible and files could be accessed. Unfortunately, very soon, the same symptoms developed in the replacement HDD. I presume it's a virus. Questions are:- 1. How can I fix it? 2. How could the external box get the PnP info from the HDD to find partitions and files when the BIOS couldn't? 3. If I can't fix the HDDs, how can I copy the files across without spreading the infection? 4. Where does a HDD store its PnP info? 5. How can I edit the MBR? I'll be very grateful for any clues

Doesn't sound like virus activity. Seems like more of a hardware problem to me. How are the drives physically connected? Have you tested the cables and controllers? Have you run any hardware diagnostics on the system? "So won’t you give this man his wings What a shame To have to beg you to see We’re not all the same What a shame" - Shinedown

Thanks Jennifer Since posting, had a piece of luck - model name/number appeared in BIOS/CMOS after several CMOS changes/saves, so was able to access HDD, rewrite MBR and then do virus purge. AVG reported a Trojan disguised as a patch. Unfortunately, deleted it without noting details, which might have been useful here. Thanks anyway for your trouble Kind regards John Nixon