Thank you. That appears to be the answer I was looking for. Actually, I don't want to hide any folders and is my reason for having set this view intentionally. I want everything that is on my computer to be in plain site. I realized that these were hidden files alright, but it was the necessity of keeping them that puzzled me. I figured they had limited to no use and with what you have told me, that's true. In the case of my laptop, which is older and has only an 80 gig HD, knowing they were there and having eliminated them, I freed up a significant amount of real estate. Actually, I thought I did have SP3 already. I'll take a look at that when I get back to that laptop at my office. As far as their contribution to computing speed, I'm glad to know these files don't cause a slowdown. They just pile up and fill space. Thanks again for the answers.