Windows 11: Bug fix shrinks some 500 GB system files to just a few MB

A bug in Windows 11 caused the size of a certain system file to increase unnoticed for months. On some systems it grew to up to 500 GB. The current Patchday update now provides a solution to the memory problem.

Update against full SSDs

With the current Patch Tuesday update for Windows 11, Microsoft has fixed a memory bug for all affected users. An error allowed a specific system file to grow uncontrollably to up to 500 GB, massively reducing storage space. After the fix was already delivered as part of an optional update at the beginning of the month, the bug fix is ​​now landing on the PCs of all users of versions 24H2 and 25H2 with the regular July update KB5101650. The log file CapabilityAccessManager.db-wal is affected. The associated service manages applications’ access rights to hardware such as cameras, microphones or location data. It is a write-ahead log of an SQLite database in which the operating system caches changes. Normally, Windows 11 cleans the document regularly. However, this did not happen in the past on affected computers, which meant that the file continued to grow.

As Windows Latest reported that the problem occurred particularly when using programs that frequently query location data. Software such as the Dell SmartByte network tool or certain plugins for desktop customizations sometimes triggered many writes per minute. For example, while monitoring around 10,000 end devices, an administrator discovered that more than half of the systems had an excessively large log file. In one extreme case, the file reached a size of 332 GB.

However, there have also been reports of files of up to 500 GB. According to internal support logs, Microsoft had been aware of the problem since May 2026, but did not communicate it publicly for a long time.

Patch stops file growth

The update KB5101650 now reliably prevents the file from growing further. One disadvantage, however, is that the storage space that has already been used is not always released immediately. After installing the update and rebooting, the file should ideally shrink to a few megabytes. Since Windows does not list the file by name in the normal storage settings, users must manually check the size via the command prompt with admin rights using the following command: robocopy “C:ProgramDataMicrosoftWindowsCapabilityAccessManager” “%TEMP%CAMCheck” /L /B /R:0 /W:0 /BYTES /NP

Some manual deletion necessary

If the system does not release the storage space independently after the update, users must intervene manually. However, carelessly deleting the file during operation can have negative consequences. Some users report problems with Wi-Fi connections or missing permissions after interventions. To avoid difficulties, experts advise deleting the file exclusively in Safe Mode. This ensures that the Capability Access Manager service is not active. This means that the log data can be safely removed if the update alone does not help and the storage space remains occupied.