Starting yesterday my Windows XP began to take over 20 min. to startup. It sits at the windows loading screen for a few minutes, then at a black screen for a few minutes, and finally at the windows desktop showing only my desktop background for a few minutes before it is ready to use. I did not install any software or change anything on my computer prior to this problem occurring. I know friends that this has happened to but no one knows the remedy. Any help would be great.