You may have encountered this annoying message often in windows 7 when trying to delete or rename a folder. Even though the folder is already “empty”, when actually it isn’t because it still have that hidden thumbs.db file that you can’t just remove.
The simple fix, unhid the thumbs.db file.
1. On the left side of the folder window, click Organize button then choose Folder and search options.
2. The Folder options will appear. Click the View tab and scroll down a bit to uncheck “Hide protected operating system files”.
3. A confirmation message will appear, click Yes.
4. Now we can see the thumbs.db file.
5. If you’re trying to delete the folder, this popup may now appear. Click yes. Now you have your folder deleted!