well i did a clean install to windows xp and for some reason when i went to try to set permissions to certain users i dont have the security tab for me to give certain permissions to users why

I ran a registry cleaner yesterday as well as a defragger. I have used both of them before without a problem. Now my desktop picture is gone and was replaced by Active Desktop. It will only replace the desktop picture with the one from Windows XP. The background I want doesn’t become the background. Any ideas?
Any help will be appreciated.

I type an entire sentence befor I see it when I am using my yahoo mail. When I look in my "add or remove programs" I see about 20 updates for Windows XP could this be part of the problem there are a couple updates per month… Other with what?
Thats- otherwise what?

I’m currently running on Windows XP. I want to install Windows Vista. When I installed Windows XP, the setup ran when I first restarted the computer. I tried doing that with Vista, changing the priority to the DVD drive. It totally skips the DVD drive and just boots up my hard drive? Does anybody know why?

Im looking for simple things I can do to clean up my computer after using the internet.
I am using windows vista and I have another computer that uses windows XP.

Please list what to do and details thank you.