Theres always the possibility that you have spyware. Not from windowblinds (I hope

), though, but from websites that download stuff for you, even if you don't ask for it. A good tool to fight it is Ad-Aware. It scans your computer for spyware and gives you the option to delete it. It also scans cookies which can be deleted also, but you'll need to sign in again to this site. No biggie. The site to download it is here http://www.lavasoftusa.com/ . I'm not sure how much spyware can lag your computer, though, but its always a good thing to get rid of it.