In the past week my computer has become "very" slow. After a reboot there are hours of disk activity (usually something to do with lsass,exe) but it has done that for years, after a few hours it seems to settle down and run ok. However recently things have slowed up so much that pages are taking several minutes to load. Through trial an error I think it might have something to do with AVG because if I temporarily disable AVG then after a while it seems to run normally again. If I restart AVG it slows up again. I don't recall loading anything recently that may have changed things. Running Windows XP Home SP3
Not sure where to go from here to sort this problem out and would appreciate any assistance anyone can give.