Clearing your temporary files out of your internet cache memory could help with performance. Others could better explain what's going on, but if you are running Internet Explorer, try this:
Go to the Tools menu and select Internet Options. Where it asks about deleting your temporary internet files, delete all that stuff involving cookies, temp files, etc etc.
I would also restart my computer if you haven't done that recently. These things MIGHT help. But it's about all I have to offer.