I personally have disabled the thumbnail creation on my system as I see it more of a way to leak private information. Anyone with access can look at the contents of thumbs.db files to check out what a user has been looking at in the past. This may even work if the images used to generate the thumbnails are long gone.

Thumbcache Viewer is a new portable Open Source program for Windows to display the contents of a thumbcache_*.db file. The developer has created a command line and graphical user interface version which need to be downloaded separately.

The first thing that you need to do after starting the program is to click on File > Open to load a file browser to locate and load a thumbcache_*.db file from a connected storage device.These files are located only on Vista and Windows 7 systems, and located in the following folder: %homedrive%\Users\%username%\AppData\Local\Microsoft\Windows\Explorer

Please note that you may need to disable the preference to hide important operating system files automatically on the system to see the thumbs.db files in that file browser. The program displays the files, filenames, sizes, checksum and hash information in its interface.

The selection of an entry in the database displays the thumbnail image in a small viewer window. You can move around with the mouse or arrow keys and scale the image with the + or – keys to zoom in or out of the thumbnail image. Alternatively, you can use the mouse wheel to zoom in or out as well.

Files can be renamed by clicking again on the selected thumbnail in the table. Just enter a different file name and press enter to complete the process and save the new file name.

You can download the latest version of Thumbcache Viewer from the Google Code project site. Windows XP users can alternatively Thumbs.db viewer and cleaner which I reviewed back in 2007.

The option to disable the caching of thumbnails and thus the generation of thumbs.db files is available by following this path: User Configuration > Administrative Templates > Windows Components > Windows Explorer. The entry “Turn off the caching of thumbnails in hidden thumbs.db files” is not configured by default. Enabling that policy will prevent that thumbs.db files are created.

This does not delete the thumbs.db files that are already stored on the computer system. That’s where the software Thumbs.db Cleaner comes in handy. It can be used to crawl a hard drive or specific directory for thumbs.db instances. All files that are found will be displayed in a list with information like the file size, data of creation or modification and file path.

Checkboxes are used to mark files for the cleanup process with all entries selected by default. A click on the Clean button will remove all selected thumbs.db files from the computer system. Thumbs.db cleaner is a portable Open Source application for the Windows operating system that can clean thumbs.db files effectively from a computer system. Ideal for a sweep after disabling the automatic generation of thumbs.db entries in Windows. (via JKWebtalks)

Each image is represented as a jpg image in the thumbs.db file which makes it relatively easy to extract those images again. The thumbnails are stored in a centralized location in Windows Vista with the name thumbcache_xxx.db where xxx is a number between 1 and 999. That folder is located at %sysroot%\Users\Owner\AppData\Local\Microsoft\Windows\Explorer.

A flexible small tool that can extract all images from thumbs.db files is Thumbs Extract. It’s a command line utility and the command is ThumbsExtract.exe path to thumbs.db, for example ThumbsExtract.exe c:\thumbs.db if the file is located on the c:\ drive.