Windows 10 has a small visual bug where, when you open File Explorer and navigate to a location with folders in it, some of those folders have a black box around the standard folder icon. The black background on folders appears at random; some folders may get it while others may not. Refreshing the screen doesn’t do any good. Here’s how you can fix it.
Fix black background on folders
In order to fix the black background on folders, you need to first open the Disk Cleanup tool. You can search for it using Windows Search. Run disk cleanup on your Windows drive i.e., the drive that Windows 10 is installed on. Make sure that the Thumbnail option is selected, and click Ok. When prompted, confirm that you want to delete the files.
Next, you need to delete the icon cache that Windows 10 has built. To do that, open File Explorer and navigate to the following location;
Here, look for a file called IconCache.db and delete.
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Once you’ve done that, open File Explorer again and go to the following location. Select all the files here, and delete them. If Windows 10 prevents you from deleting some of the files, click the Skip button and delete the ones you can.
Finally, you need to Restart File Explorer. You can do this from Task Manager. Open Task Manager and look for Windows Explorer on the Processes tab. Select it, and click the Restart button at the bottom right. When File Explorer restarts, the black background on folders will be gone. For good measure, restart your system.
This will fix the problem however, since it has to do with the icon cache, it may reappear. There’s no known cause behind this and since it’s a very small bug compared to everything else that goes wrong with Windows 10, it’s not exactly high priority. There are bigger problems that Microsoft still hasn’t fixed like Windows Search still not working for a lot of users so this one isn’t going to be resolved any time soon. If the bug ever surfaces again, you can run through the fix and get your folder icons back to normal.
Another solution, although a very crude one, is to delete the folder (after backing up its contents) and create a new one in its place. You can then move its contents back and hope the new folder doesn’t have the same black background.