Crashes at Stop of Search for Files and Folders

On Windows XP with all updates installed: 'Search for Files and Folders'
works fine until I either click on STOP or it finishes; then the screen
freezes and I must use Task Manager to exit Search. I then see my desktop
wallpaper, and the desktop icons populate over a few seconds. This problem
may or may not be connected with my adding an external hard drive; I am not
sure whether the problem started at that point.