Have a look at
blackviper.com. The site can help you to disable unnecessary xp processes.
For anti-virus,
eset NOD32 seems pretty quick for me, but it's a commercial product.
For mal-ware, you could also do some reading about
HijackThis. There are some good forums which give help/discussion about using this tool. It's not an easy one to master, though it is very handy if you have plenty of time to put into using it.
If you are getting some mal-ware, as you've suggested, then ceasing to use your security programs is probably not the best next move. Do your security apps find any issues?
Windows still benefits from a re-install every so (too) often.
