I've got a bad infection on Windows XP. Firefox is running slow, there are Vimax ads all over the place, and tech websites/forums are inaccessible (I'm posting this offline). The worst part is that my usual arsenal is also disabled: AVG (installation fails), HijackThis (won't start), and Malwarebytes (the installation runs fine, but the program just won't start). I'm posting here because Malwarebytes has been my fail-safe software for months now. I've tried renaming the setup file, no luck there. I can't post any logs, so all I can do is tell you what I've tried. In addition to the programs I've already mentioned I've successfully ran ATF cleaner - on effect. I've also booted the computer from a Avira rescue disk and ran the virus scan. Again, no effect. Most recently I tried ComboFix, but entering the command "%user..." doesn't start the program. It's exactly like trying to start Malwarebytes or HijackThis. The hourglass shows for a split second, then nothing. I'm reaching my wits end. I really don't want to scrub the disk and reinstall XP, but unless someone here has some ideas it looks like that's exactly what I'll have to do.