When you open Windows File Explorer and access a folder containing pictures, it generates thumbnails of all the pictures so that it is easier for the user to find the picture files. Next time you open that folder, Windows skips generated thumbnails for the pictures for which it has already stored thumbnails in a special file called thumbnail cache database file. These files are generated only if you have enabled to view thumbnails instead of the file icons in the File Explorer settings.
For different resolutions, Windows created different thumbnail cache files and stores them in the user profile folder. Typically these files are stored inside the %LocalAppData%\Microsoft\Windows\Explorer folder. You will find files like thumbcache_32.db, thumbcache_96.db, thumbcache_256.db, thumbcache_768.db etc. All these files contain thumbnails of different sizes generated by Windows File Explorer.
Using the popular 7-Zip software, we can extract pictures from these thumbnail cache files. But this requires installation of some extra 7-Zip plugins in the following manner:
- Open the installation folder of 7-Zip in File Explorer. Usually this is located at C:\Program Files\7-Zip\.
- In this folder create a sub-folder named Formats.
- Download Thumbs7z plugin from https://www.tc4shell.com/en/7zip/thumbs7z/ and extract all the files in the Formats folder that we created in step 2 above.
- Now we can right-click on any thumbcache_*.db file and choose to open it with 7-Zip. In the 7-Zip window, you will be able to view all the pictures from inside the thumbnail cache database file and extract them to any folder you want.
Using this method, we can extract the contents of any thumbnail cache database file created by Windows File Explorer on Windows Vista, Windows 7, Windows 8.x and Windows 10. The files created by Windows XP are also supported but they are not located in the user profile folder, instead they are created in the same folder as the actual pictures.