PC (core2 duo) was running slow for about 15 minutes after starting… after which, it would speed up a bit, and the hard drive light would stop flashing like crazy.
But as soon as something was started (eg internet explorer), everything would slow down again for about a minute or so.
Task manager showed that the main culprit was sbamsvc.exe
So, I start investigating and find its a part of Bigpond Internet Security (BIS) called SunBelt.
OK, I’ve never liked BIS, and in this case, I advocated upgrading to Windows 7 – 64-bit, which meant I would be able to remove this annoying excuse for internet security.