He has XP, Franko. Probably hasn't been updated and (Nick - VW LupoTD) is right, it likely needs to be scrubbed. This isn't the first time we've tried to rescue Justin's PC.
Justin has a bad habit of just clicking on things that pop up - in the past, he got himself infected with AV2009, QDRPack, and a couple other minor exploits, despite the warnings.
My suggestions here are:
a] SuperAntiSpyware (he has it installed already) - update first, then scan.
b] MalwareBytes (from MalwareBytes,org) - install, update, full scan
c] Trend Micro Housecall (
http://housecall.trendmicro.com) - full online scan
Once he has the hijack disabled, he should be able to run ccleaner (also already installed) to wipe his temp files and cache. I would suggest a run of HijackThis! to give us a registry-level peek at what he picked up, but I suspect that's too technical a task.
He might be able to ditch this with a systemrestore, but I don't have time to walk him through it right now, and I have my doubts that it can be fixed that way.
Guys - work together, go slow, be very clear. Too many divergent directions will just mess things up. He may well need to do a complete wipe and build, but I doubt he can do it from our directions, and once he stats, he's cut off from help.
Nick - great idea on the newly-built box with remoteassist... that sounds like the ideal solution - but remember he will have a pile of pictures/files he'll need to keep.