Worked on a friends box that had task manager disabled recently. AVG didn't find anything after a full scan. Makes me wonder if he still might have something.
Yep.....he probably does.
Sometimes systems get so badly infected with stuff, that by the time you get them cleaned up, they still don't work right. Good programs get corrupted.
In cases like that, you're better off to just back up their data, put the OS disk in, re-partition the hard-drive and re-install the OS.
One other thing. If you have not already done so.....you need to insure that you are up to date on all of the Microsoft updates....including Service Pack III. Having these updates will help prevent a lot of the crud that you pick up.
Also....Install Windows Defender.
AVG's newest version has built-in anti-spyware as well.