Finding the Thumbs.db files in Vista
While using Windows Explorer (in XP or 2003), if you set the “View Icon Type” for a particular folder to either Thumbnail or the Filmstrip view, a Thumbs.db (which is a database file) is generated and stored in the same folder. These database files store small cache versions of the various graphical content of the different files in the folder. This way, the thumbnails do not have to be generated for display every time you access the folder.
Although in the Media Center Edition of Windows XP, thumbnail previews of video files are supported, they are stored in an ehThumbs.db file instead of a Thumbs.db database file. In addition, all of the thumbnail database files are typically stored in the ‘Hidden’ mode.
Windows Vista, however, has a different system regarding the thumbs.db files. Here, the thumbs.db/ehThumbs.db files are not scattered around in the folders. Instead, the thumbnail database files that are generated in the folders are stored in one single directory that allows centralized storage/access to all the thumbnail database files. The location of this centralized directory is:
\Users\[User Account Name]\AppData\Local\Microsoft\Windows\Explorer
In the above directory, you will find files with the “thumbcache” prefix – they will have a filename of the form: thumbcache_xxxx.db.
This move to a centralized thumbnail database for Vista reduces the clutter in your normal directories and prevents unnecessary and accidental deletion of Thumbs.db files. As it is not possible to delete the thumbs.db files in this case, it is best to use Disk Cleanup whenever you want to delete the thumbnail cache stored at the above location.