System Won't Complete AV Scan

I use V-Com Fix It as my suite to handle system maintenance including antivirus protection. When I try to run a scan, it goes through memory scan fine and starts working on the actual files. At some point it chokes on a file and the system starts acting strangely. The icons in the taskbar either disappear or duplicate, but when I run the cursor over them they usually disappear. If I try to launch a program I'm given various error messages like it's a bad image or not a valid system 32 file. The only solution is to reboot and that can usually only be accomplished by hitting the reset button on the case. (After posting this message, I'm going to do it again and post more of the messages I get) My CounterSpy programs scans fine, with no suspicious problems. I got Karsperky's online virus scanner to run and it didn't find anything suspicious either.

I think the problem surfaced shortly after installing .NET Framework, but I'm not sure that's the problem. I've tried uninstalling .NET Framework, re-installing version 2.0, but the same problem occurs. I've uninstalled and reinstalled Fix It. I've tried using MSCONFIG to do a diagnostic boot with no mandatory service running, but still had the problem. The problem has also happened on its own without the virus scanner running. The autofile scan was probably running in the background though. The PC had been sitting for a few hours.I REALLY don't want to do a complete reinstall of XP if I don't have to. So, I'm hoping somebody here can come up with some other stuff to try.I'm running XP SP2, Fix It 7, CounterSpy 2, Kerio Personal Firewall.