If you're using IE, this is pretty much a given these days, that spyware will cause problems.
Download AdAware and Spybot, let them purge your system as much as possible. Then download a copy of Mozilla Firefox and stop using IE, for anything except Windows Update.
I developed a problem when clicking on a hyperlink I go to the new page but it immediately comes back and I have to rewpeat the action and then it stays. This is annoying. I'm using Win.XP Home with IE. for the browser. I have 512mem. with 70HD. which should be plenty of both. I have defragged and even bought registry mechanic. Any suggestions Please