Clean up system files not working

Question

Some recent Windows 11 Pro Update (likely 25H2) or Microsoft Edge Version 142.0.3595.53 is hogging ~5G extra disk space on my Surface Pro and I'm unable to recover it using Cleanup System Files. Normally Cleanup System Files shows some space (typically 100's of MB) that is reclaimable and after I trigger it, I recover a few GIG's. Currently it's showing 190 MB of System Files which can be cleaned up but the cleanup is not getting triggered even though I have tried to invoke Cleanup System Files multiple times from different interfaces (including after restarting). So, the 190 MB number which shows as reclaimable doesn't change, when in reality if the cleanup ran a couple of GIG's would actually be freed up and the 190MB number would drop to 0. Is there a way to really force cleanup of unused system files & temp caches used by apps? Also is there a way to track if Edge downloaded something huge to some hidden cache directory (because my storage went to 0 when browsing Yahoo in Edge, with a popup saying some package was taking that space).

Answer 1

Hi RK,
Welcome to Microsoft Q&A forum. I'm happy to help.

The 190 MB portion likely consists of temporary files currently in use by applications or the Windows system, which is why "Cleanup System Files" cannot remove them. You may be able to delete some of these files by booting into Safe Mode and then running "Cleanup System Files".

The extra 5 GB of disk space may be related to the Windows Update cache. You can check two locations: C:\Windows\SoftwareDistribution and C:\Windows\System32\catroot2. If you recently upgraded Windows, there might be a C:\Windows.old folder. You also can manually clean up Recycle Bin by running this command in Command Prompt as Administrator: rmdir /s /q C:\$Recycle.bin

Not only the Windows system and Microsoft Edge, but most applications create temporary files to store data. Typically, these files are managed and deleted automatically; however, sometimes they are not properly cleaned up and remain on the system. My advice is that you do not need — and should not — perform cleanup tasks frequently unless your free space is low. Modern systems use SSDs for "C" drive, which have a TBW (Total Bytes Written) limit. Unnecessary frequent cleanups increase the total data written and can cause your SSD to wear out faster.

The "C" drive space is filling up not only by temporary files but also by files created for each application’s purpose. While temporary files are easy to delete, components like indexing are harder to optimize or remove. Over time, the indexing database can grow significantly as you use Windows.

For convenience, my suggestion is ignoring the temporary files. One day, may be next few years, when you realize that your system needs a smoother experience, then you may back up necessary data and perform a clean install.

I hope that above information is helpful to you.

If you have further questions, please feel free to let me know.

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Answer 2

After installing today's "2025-12 Security Update KB5072033 (OS Builds 26200.7462 and 26100.7462)", followed by running disk cleanup with cleanup of System files selected, I was able to recover the remaining missing couple of Gig's as cleanup of system files finally worked as expected. For some strange reason KB5072033 did require 7+G to download & install!

I'm really surprised that Windows Update still doesn't know how much space an update will require and keeps trying (humongous) updates which fail to install due to insufficient disk space. These failed updates seem to leave behind files which don't get cleaned up and require tricks like force deletion of "C:\Windows\SoftwareDistribution" folder.