If you've ever opened a folder with thousands of images or videos and watched your PC slowly redraw every thumbnail like it's stuck in 2005—you're not alone. This happens because Windows 11 keeps a limited cache of your file thumbnails (also known as IconCache), and sometimes it just wipes them out, leaving you with that painful wait.

But here's the good news: you can increase the thumbnail cache size and reduce how often Windows forgets your folder thumbnails. Let's walk through why this happens and how to fix it.

Why Windows Keeps Deleting Thumbnails

By default, Windows stores thumbnail previews in a cache file to make folder browsing faster. But it also aggressively clears this cache during:

If you're a photographer, content creator, or someone with a giant image collection, this behavior can be seriously annoying.

The Fix: Increase the Icon Cache Size in the Registry

To get Windows to remember more thumbnails, we can tweak a registry setting that tells it to allocate more space for icon storage. 

Step-by-Step: How to Increase the IconCache

Press Win + R, type regedit, and hit Enter.
Navigate to:

In the right pane:

Double-click on it and set the Value data to something larger, like:

Click OK, close the Registry Editor, and restart your PC.

That's it. This lets Windows store more thumbnail data so you don't have to keep waiting for it to regenerate previews every time.

Optional: Rebuild the Cache Once (for a Fresh Start)

If your cache is already bloated or buggy, it's a good idea to clear and rebuild it after increasing the size.

Here's how:

This deletes the old cache and restarts Explorer. The next time you browse folders, Windows will generate new thumbnails—and now it has more space to store them! 

Bonus Tips to Keep the Cache Safe

Final Thoughts

Windows 11 wasn't really designed with massive media libraries in mind, but with a few small tweaks, you can make it play nice. By increasing the icon cache size, you'll spend less time waiting and more time actually working with your files.

If you browse huge folders every day, this simple fix can make a world of difference.