If you’re currently experiencing problems with storage space on your Windows 11 PC, it may not be your own fault—even if you’re hogging a massive number of files and/or apps. You might actually be affected by a system bug that can take up as much as 500 GB of storage.
Buried in the patch notes for Windows 11 update KB5095093, there’s this line: “This update improves disk space usage for the CapabilityAccessManager.db-wal file.” At first glance, you might think nothing of it. But it turns out this fault can cause a system’s drive to grow increasingly full. The problem is linked to the Capability Access Manager service, responsible for app permissions in Windows.
The file in question should normally only take up a few MB of storage space, but on some PCs it can amount to several hundred GBs. In some cases, it can even fill the drive completely, which will significantly reduce system performance—as experienced by this Reddit user.
How to check if you’re affected
Simply checking the list of apps installed on your system and taking up space on your drive (which you can do under Windows Settings → System → Storage) usually won’t reveal the problem. This is because it doesn’t show which folder is causing the increased storage usage. You can only see whether the drive is already full or not.
Windows Latest recommends instead using an app like TreeSize, WinDirStat, or WizTree (one of our favorite apps for checking PC health) to search for large files and spot where CapabilityAccessManager.db-wal is among them. It it’s several GB in size, you’re affected by the bug.
Alternatively, you can use the Windows Command Prompt with administrator rights and enter the following command:
robocopy "C:\ProgramData\Microsoft\Windows\CapabilityAccessManager" "%TEMP%\CAMCheck" /L /B /R:0 /W:0 /BYTES /NP
What you can do
Apparently, this issue has been present in Windows 11 for some time, as the first reports of it date back as far as a year ago. Microsoft has indirectly acknowledged the problem with a fix for it, which is already available in the June 2026 optional update but will be rolled out to all users in next month’s July Patch Tuesday update.
You can install the optional update by checking for update KB5095093 via Windows Update → Advanced options → Optional updates.
If you’re affected by the bug, you should avoid making any unauthorized changes to the file (like deleting it outright) or attempting to uninstall the Capability Access Manager, as this could lead to further errors.
By the way: If you’re using Windows 11 Home, you’re missing out on the many benefits of Windows 11 Pro. To learn more, see our comparison of Windows 11 Home and Pro. If you want to upgrade, snag it for cheap in the PCWorld Software Store: now just $59 instead of $99.
