You can clear the Windows thumbnail cache with Disk Cleanup, then let File Explorer create previews again as you browse. If app or shortcut icons are blank or wrong, rebuild the separate icon cache only after trying an Explorer restart. Neither task requires deleting your pictures, and neither is a reliable fix for a drive filled by other kinds of data.
Clear thumbnails with Disk Cleanup first
Open File Explorer > This PC and note the free space on your Windows drive, usually C:. Close any folder windows that are showing many pictures or videos. From Start, search for Disk Cleanup, open it, select the Windows drive if asked, and wait for the scan. In the list, select Thumbnails. Review every other checked box and clear any you did not intend to clean. Choose OK, then Delete Files.
Microsoft's drive-space instructions identify Thumbnails as a Disk Cleanup category on Windows 10 and 11. You do not need to press Clean up system files just to reach that category. If Disk Cleanup shows no meaningful size for thumbnails, it is telling you that this particular cache is not your main space problem. Do not select Downloads or Previous Windows installation(s) merely to increase the displayed total; those entries have different consequences.
The immediate cost is that previews may load slowly or appear as generic icons while Windows builds them again. If a thumbnail was the only convenient visual clue to a file, you can restore the view by reopening its folder and waiting for the new preview. Disk Cleanup removes generated previews, not the source photos or videos. Check the actual files before assuming a missing preview means missing data.
After cleaning, open the same photo folder and switch to Medium icons or Large icons from File Explorer's View menu. Give Windows time to regenerate the visible previews. Recheck free space in This PC. The reclaimed amount may be small, and the cache will grow again as you browse; that is normal behavior, not proof that cleanup failed.
Decide whether the problem is thumbnails or icons
A thumbnail is a small preview of a file's content. An icon is the symbol Windows uses for an app, shortcut, folder, or file type. They can look similar in a folder window, but clearing one cache does not always fix the other. If photos open normally but their preview tiles are blank, begin with Thumbnails in Disk Cleanup. If shortcuts on the desktop, taskbar, or Start show blank or incorrect app symbols, investigate the icon cache instead.
Before deleting any icon cache file, save your work and restart Windows Explorer. Press Ctrl + Shift + Esc to open Task Manager. Find Windows Explorer in Processes, right-click it, and select Restart. The taskbar and open File Explorer windows may briefly disappear and return. If the icons look correct afterward, stop there. This reversible restart often refreshes what you see without removing a cache file.
If only one shortcut is wrong, also check that its target still exists. Right-click that shortcut, open Properties, and look at the Target field on the Shortcut tab when that tab is present. A broken shortcut or removed app will not be repaired by rebuilding cached images. For a wider storage problem, the AppData guide helps separate caches from application settings and saved data.
Rebuild the icon cache when icons stay blank
Microsoft's blank-icons troubleshooting steps give a narrow procedure for %userprofile%\AppData\Local\IconCache.db. Save open work first: ending Explorer closes the desktop shell and its open folder windows. Keep Task Manager open until Explorer has restarted so you have a way back if the desktop disappears.
- Press
Ctrl + Shift + Esc. In Task Manager > Processes, right-click Windows Explorer and choose End task. - In Task Manager, choose File > Run new task. Enter
cmd.exe, select the option to create the task with administrative privileges, and choose OK. - In Command Prompt, run
cd /d "%userprofile%\AppData\Local", thendel IconCache.db /a. Type the commands exactly; the second names one cache file, not the whole Local folder. - In Task Manager, choose File > Run new task again, enter
explorer.exe, and choose OK. Wait for the taskbar and desktop to return, then check the affected icons.
The risk here is interruption to open folder windows and unsaved work when Explorer ends. Save first. If the command says the file was not found, do not substitute a broad delete command; restart Explorer and continue diagnosis. If the shell does not return, Task Manager's File > Run new task > explorer.exe is the recovery step. Windows rebuilds the deleted cache as needed; there is no reason to move or erase the rest of %LocalAppData%.
Some Windows installations also show files beginning with iconcache in %LocalAppData%\Microsoft\Windows\Explorer. Their names and locks can vary. The targeted Microsoft procedure above is a better first step than deleting every file in that directory. If blank icons persist, inspect the shortcut or app itself and follow the later Microsoft troubleshooting steps for that symptom. Do not edit the registry merely because a cache rebuild made no difference.
When previews remain missing
First confirm the file opens in its usual app. In File Explorer, try a view that displays thumbnails, such as Medium icons or Large icons, and wait. A new cache cannot generate a meaningful preview for a file Windows cannot read or a format for which it has no preview handler. It also cannot recover a photo that was actually deleted. Look at the full filename and extension before changing more settings.
Do not repeatedly clear the cache to chase a missing thumbnail. Each cleanup discards previews Windows then has to recreate. If the image opens but only one file has no preview, focus on that file or its app. If every folder looks wrong, test another file type and check whether icons are affected too. Keeping those two symptoms separate prevents a storage cleanup from turning into a broad repair attempt.
For disk space, compare the category's estimated size with the space you need. Thumbnail and icon caches are only one part of the system drive. The Windows Temp guide covers temporary files that require a different decision. If free space barely changes after this cleanup, inspect larger folders before repeating it; deleting the same regenerated previews will not solve a separate storage source.
Reviewing these caches with AiCleanDisk Pro
AiCleanDisk Pro lists thumbnail and icon caches among its auto-clean items, with a risk level and a confirmation dialog before cleaning. Scanning the system drive and regular auto clean are free; scanning other drives and AI analysis require a license. Cleaned files go to the Recycle Bin by default, while operations performed through system commands can bypass it and the dialog says so. The app can help you review these cache categories alongside the rest of your drive, but keep a broken shortcut or unreadable image as a separate troubleshooting problem. See the product overview for the available scanning and cleaning options.
Keep the result in perspective
Use Disk Cleanup for thumbnails, and reserve an icon-cache rebuild for incorrect app or shortcut symbols that survive an Explorer restart. Both caches can return because Windows uses them to display files quickly. A small cleanup result is useful information: it tells you to look for the actual large folder instead of repeatedly deleting visual previews.