Whenever we open a folder that contains media files (for example, image files), we get a small preview called a thumbnail. Thumbnails are again part of the media and therefore need their own space and use some system RAM. To prevent the system from giving up its resources every time we open the folder, Windows stores "thumbnail caches", which are basically temporary files that help the folder load instantly.
However, every time we shut down or restart the system, the cache is cleared. So it's an amazing fact that every time we reboot the system it takes time to open heavy folders. This could be avoided if we could prevent Windows from clearing the thumbnail cache on every reboot.
Try the following methods for the same:
Solution 1: Disable the SilentCleanup task in Task Scheduler
1] Press Win + R to open the Run window and type the command taskchd.msc. Press Enter to open Task Scheduler.
2] Go to the location Task Scheduler >> Task Scheduler Library >> Microsoft >> Windows >> DiskCleanup.
3] In the right pane, right-click the SilentCleanup task, then click Disable.
4] Close Task Scheduler and reboot the system.
Solution 2: Uncheck the Disk Cleanup Thumbnails options
1] Go to This PC and right click on C: (where C: is your system drive).
2] Select Properties to open the System Drive Properties window.
3] On the General tab, click Disk Cleanup. It would take some time to calculate the amount of data to clean.
4] Uncheck the Thumbnails option from the list and click OK.
It will start cleaning unnecessary files from the disk without thumbnail cache. However, it won't automatically clear the thumbnail cache in the future either.
Solution 3: Prevent third-party software from deleting the thumbnail cache
Before fixing anything with Windows, we need to make sure that no third party software is clearing the thumbnail cache. One knows that the free software that does the same thing is CCleaner. You can deselect the thumbnail cache option. You can try similar procedures with other software products.