Recent reports have surfaced regarding a notable bug in Windows 11 that can lead to significant disk space loss, with some users experiencing reductions of up to 500GB. The issue stems from a system file known as CapabilityAccessManager.db-wal, which is part of the Capability Access Manager Service. This file is responsible for managing permissions for applications to access sensitive features such as the camera, microphone, and location services.
Under normal circumstances, this file should occupy no more than a couple of megabytes. However, the bug has caused it to balloon to alarming sizes, as highlighted by a Reddit user who first reported the issue over a year ago. The file’s expansion is attributed to its role in maintaining a write-ahead log of changes before they are committed to the main database.
How to tell if you’re affected
If you suspect your system may be impacted by this bug, checking the size of your Windows system files is a straightforward approach. Navigate to Settings, select System, and then click on Storage. Under the initial bar image, click the link for Show more categories. If the System & reserved category indicates a size of two or three dozen gigabytes, you are likely unaffected. However, if it exceeds 100GB, your system may be experiencing this issue.
In my own evaluations across various Windows 11 environments, I found that most systems reported sizes between 5GB and 25GB. Yet, my primary laptop showed a concerning 151GB. To pinpoint whether the CapabilityAccessManager.db-wal file is responsible, it can be located at C:ProgramDataMicrosoftWindowsCapabilityAccessManager. However, access to this folder is restricted by default, and modifying permissions is not advisable.
For those seeking a clearer picture, tools such as WizTree, TreeSize, or WinDirStat can be run in administrator mode to examine the folder’s contents. Alternatively, a simpler method involves using the built-in Robocopy tool. By opening a command prompt as an administrator and entering the command:
robocopy "C:ProgramDataMicrosoftWindowsCapabilityAccessManager" "%TEMP%CAMCheck" /L /B /R:0 /W:0 /BYTES /NPThis command will reveal the size of the CapabilityAccessManager.db-wal file. In my tests, most installations reported sizes around 57,000 bytes, but my primary laptop displayed a size of 7GB, which, while not excessive, was still larger than expected.
How to fix the glitch
Despite the bug’s persistence over the past year, Microsoft has finally addressed the issue. The June 23 optional preview update includes improvements to disk space usage for the CapabilityAccessManager.db-wal file. I have already applied this update to my Windows 11 virtual machines, although it remains pending on my laptop.
For those looking to implement this fix, the update can be accessed through Settings and Windows Update. Users should look for the 2026-06 Preview Update and select Download & Install. It is important to note that these preview updates are optional and primarily intended for IT administrators and power users. The same fixes will be included in the official Patch Tuesday rollout the following month, scheduled for July 14, which will be mandatory for all Windows users. For those willing to wait, this update should effectively resolve the file size issue for everyone.
