Binos - I just asked my other half, who dabbles in such things, if he has any ideas. He suggested a couple of things.
1. He likes Spybot better than AdAware, as he thinks it picks up more. See
http://www.safer-networking.org/
2. To see what is running on startup, and therefore is slowing the machine down, go to msconfig. To do that go to Start, run, msconfig
3. Try looking in the startup folder. It should be empty or perhaps have office. If it has other junk, it is probably slowing things down.
Good luck