My dad's Windows XP Home Pentium-4 machine has the Conficker virus, or some variant of it. The reason I know this is that he passed the virus on to his external hard-drive (in USB enclosure), a USB thumb-drive, and his Windows XP Home laptop.
Long story short: we've disinfected the external HD and thumb-drive, as well as the Windows laptop. However, the Pentium-4 desktop PC seems royally screwed. The DVD drive seems not to be working now, so even when I put a Kaspersky 10 Rescue DC in the drive and reboot, specifying CD-ROM as first boot device, we have no luck...
Managed to download and install Microsoft Security Essentials (he was running NO anti-virus initially, hence the virus), but we're unable to complete downloading of virus-definitions (presumably the virus is interfering). Safe mode, no luck. And his BIOS is too old to be able to allow booting from a USB.
Summary: I cannot get at the problem in any of the usual ways. I'm wondering if I removed the hard drive and put it in an external HD enclosure, hooked that to a PC running MSE, if we could disinfect the drive, then reinstall it in his Pentium-4 desktop PC and go from there.