If you don’t feel like diving into the Registry yourself, we’ve created a couple of registry hacks you can use.
The “Set Icon Cache Size to 4096 KB” hack sets the icon cache size to 4096 KB (4 MB).
Type cd /d “\Program Files\Windows Defender” into the Command Prompt and press the Enter key.
Type exe -signatureupdate into the Command Prompt and press the Enter key.
Here is how to repair the thumbnail cache in Windows 10.
RECOMMENDED: Click here to fix Windows errors and optimize system performance Thankfully, in Windows 10 there is a built-in ability to clean up the thumbnail cache.
If you’ve ever noticed that Windows Explorer loads icons slowly, especially when you first start your computer or open a folder with lots of files, increasing the size of the icon cache might help. If you notice that icons are displaying incorrectly, or not displaying at all, your first step should be rebuilding the icon cache (in Windows 10) or the thumbnail cache (in Windows 7 and 8).
That process basically amounts to finding and deleting the cache file so that Windows rebuilds it on the next restart.
This works in most cases, where the issue is originated due to a system corruption.
The icons for your files and programs are stored in a cache, so that Windows can display them quickly instead of having to load them from source files every time.
And definitely back up the Registry (and your computer! Open the Registry Editor by hitting Start and typing “regedit.” Press Enter to open Registry Editor and give it permission to make changes to your PC. Double click the new “Max Cached Icons” value you created to open the Edit String window. We’ve found that after about 4096 (4 MB), you pass the point of diminishing returns, so we suggest setting it at 4096 and then adjusting later if you need to. And if you want to try a different icon cache size, just follow those steps again.