As part of its July Patch Tuesday update, Microsoft addressed a significant issue affecting Windows 11 users, alongside a host of security vulnerabilities and new features. A particular bug related to the CapabilityAccessManager.db-wal file had been causing an alarming consumption of storage space, with some systems reporting usage as high as 500 GB.
This bug stemmed from the Capability Access Manager, a Windows service responsible for managing app permissions. Under normal circumstances, the CapabilityAccessManager.db-wal file should occupy only a few megabytes. However, due to this glitch, it ballooned to several hundred gigabytes on certain PCs, leading to unnecessary storage strain even when ample space was available.
Resolution Through Update KB5101650
With the release of update KB5101650, Microsoft has implemented a fix for this storage issue. Unlike some features that may be rolled out gradually, this particular resolution is designed to take effect immediately upon installation. In the patch notes, Microsoft succinctly noted:
[Storage] This update improves disk space usage for the CapabilityAccessManager.db-wal file.
However, Microsoft has not clarified whether existing oversized WAL files will automatically resize. Reports from users who had previously installed an optional June update indicated that their files remained large even after the update, only returning to normal size after manual deletion.
To ensure your system is functioning optimally post-update, it is advisable to check the size of your WAL file. This can be accomplished by entering the following command in the Windows Command Prompt with administrator privileges:
robocopy "C:ProgramDataMicrosoftWindowsCapabilityAccessManager" "%TEMP%CAMCheck" /L /B /R:0 /W:0 /BYTES /NP
Alternatively, users may opt for third-party tools such as WizTree, TreeSize, or WinDirStat to locate the “CapabilityAccessManager.db-wal” file and assess its size. If the file is still several gigabytes, it is recommended to delete it using the proper procedure outlined in the update documentation. Conversely, if the file size has reduced to a few hundred kilobytes or megabytes, the system is functioning as intended.
This information was originally published by our sister publication PC-WELT and has been translated and localized from German.
