Geotheman, look very long and deep for malware slowing your system.
For my recent bout with a staggering computer, that meant using as many scanning engines as I could find.
GW has a solid point about system hogs, in my opinion.
CA Security did indeed slow my system and one of a friend, to a dead crawl. When it was cleaned off completely, all was back to normal.
Next in line on the resources hog is Norton Internet Security, in my experience.
Iolo System Mechanic was never a hog for me all the years I used it.
I am posting my experience and opinion, not trying for any proofs.
I don't even proof the yeast I use to bake bread!
If its bad yeast, the resulting solid bread will make the best bread pudding around.
