Thanks to both of you. I do indeed have the disc and have tried to download SP2 with the disk and from the Update Website.
I don't think I have a Yahoo toolbar and I didn't see an option to install it while trying to download SP2. Also, I clean up the computer frequently. You know, I've been trying to download SP2 for at least a year now and it is ALWAYS that same message about an application using that particular file.
Any other ideas? Thanks!