Sorry for the long subject line, but that about sums things up.
Startup takes about 10-15 minutes before the hard drive settles down to no visible activity. After the first 5 minutes, I expect little to no activity, but the task manager shows AAWservice.exe and avgrsx.exe each sucking 0-100% CPU. That's with no program turned on/running.
Many / Most operations also seem to run slowly, including just opening My Computer, but also extending to things like browsing on Firefox (latest version, just updated today to 3.5.3).
And, the fan operation is incorrect. It starts up all right with a surge, then dies down, but in a minute or so into startup, it ramps up to a high speed that remains constant while the computer is on. It's not as high as the surge during startup, but still high, and SpeedFan program shows mild operating temps (35-45 degrees C). I have already opened the case and blown dust clear. The outside of the unit does not feel hot, and it is propped up anyway to allow for circulating air underneath.
I'm using a 5-year-old NEC LavieC with Windows XP home edition. Service Pack 2 (although my Windows updater is set to automatic). 784.944kb RAM
AVG, Ad Aware Anniversary edition, Spybot, are installed, and Comodo free edition is my firewall. I update the antimalware software every 2 weeks or so and run full scans, where almost nothing is found.
Using a Buffalo wireless router.
Have no idea about sound cards.
Thanks in advance for any advice.