I saw that this problem was reported yesterday; this is when I registered to BC, which I did partly prompted by a very similar problem, which started about a week or so ago.
I was playing some game (not online), but my broadband connection was open. During the game, my antivirus software (Norton) started its daily live update. When I closed the game, it was like a small atomic bomb had landed inside my laptop:
1) Mozilla Firefox, which I'd been using for months, would not start, giving me an error message each time I tried to start it;
2) Outlook express - which I'd been using for almost 4 years - would not retrieve messages from my work email account.
3) My machine took forever to shut down and/or restart.
4) Norton had become very sluggish, either freezing or often failing to start properly when I tried to open its main window;
5) Many applications would fail to respond; even worse, I could not shut them down in any way, not even from the Windows Task Manager.
6) Each time an application failed to respond, the prompt to send Microsoft an error report would a) take forever/fail, if I tried to; or
prevent the application from closing at all, if I chose not to.
Prior to this, I'd been using Norton, Spybot SD and Stinger - all constantly updated and run for about 3 years. My machine was very fast, browsed without problems, and coped well with 6-7 simultaneous applications (nothing fancy though, just browsing and document processing - Word, Excel, Acrobat, etc)
My (I suspect novice) attempts to address the situation:
Suspecting that I'd caught some malware, I installed Spyguard, AVAST, SpyCatcher, All-in-one-Secretmaker, Ad-Aware SE and Spyblaster. Unistalled the first and last meanwhile; uninstalled and reinstalled SpyCatcher - it really slows the machine down, but finds stuff the others don't.
Spycatcher and Ad-Aware found some spyware and tracking cookies, respectively, which had been overlooked by Spybot (!). Avast detected one infected file, which it removed.
I tried reinstalling Firefox several times, including a couple of tries with the new version, 1.5.01; no success, the same error message appears. Outlook express has not recovered. It still takes a long time for the machine to restart/shut down.
I disabled the (completely useless) option to send Microsoft error reports; some applications still fail to respond much more often than 'before', but I now can close them Ok with WTM.
Overall, the situation is slightly better now: applications start almost as fast as b4, though Norton is still sluggish; browsing speed is back to normal, but IE takes 30-35 seconds to start (compared to 3 seconds b4).
I might be doing something wrong, or I might not utilise the anti-malware utilities to their full potential - for example, SpyCatcher tells me that it is "removing the threats in the background", but they're always there when I open the program.
I'd be very grateful for any advice; should I kiss my fast & nice machine from 10 days ago good bye? Is formatting the disks the only solution?
Many thanks for your help.