A file called Thumbs.db appeared on the desktop of my computer some months ago and seems to appear in new folders whenever they are created. While the file always has the same name the file size varies in different folders. If I attempt to delete these files I receive the message “The file Thumbs.db is a system file. If you remove it one of your programs may no longer work correctly.” Is this really a vital file and how do I stop its annoying habit of appearing in any new folder I create? The computer is running Windows XP.

Graphical file formats, such as photos and movies, generally display a thumbnail as their file icon when viewing listings of such files within Windows Explorer. This allows you to immediately see a small preview of that file without having to open the file, making for much more convenient browsing of such graphical files. The Thumbs.db file stores a cache of these thumbnail images. This means that each time you open a folder containing such graphical files it does not need to re-generate thumbnails on-the-fly, but instead can read the thumbnails out of the Thumbs.db cache file. This has significant performance benefits if you have a large number of graphical files in one directory. This file is usually hidden, but I imagine that you have the display of hidden files and folders enabled which is why you can see the file. To hide the file, go to the “Tools” menu in Windows Explorer > “Folder Options”. Click the “View” tab and select “Do not show hidden files and folders” then click OK. More information on the Thumbs.db file can be found at en.wikipedia.org/wiki/Windows_thumbnail_cache .