Microsoft Fixes Windows 11 Bug That Could Consume Hundreds of Gigabytes of Storage

Microsoft has quietly fixed a Windows 11 bug that could cause the operating system to consume hundreds of gigabytes of storage space. The issue was resolved as part of the July 2026 Patch Tuesday update through KB5101650, alongside the month’s record-breaking security fixes and new Windows 11 features.

The bug affected the Capability Access Manager service, causing a system database log file to grow abnormally large and unnecessarily fill users’ drives.

What Caused the Storage Issue?

The problem centered on the CapabilityAccessManager.db-wal file, which belongs to the Windows Capability Access Manager service responsible for managing application permissions.

Under normal circumstances, the database write-ahead log (WAL) file occupies only a few megabytes of disk space. However, a software bug caused the file to grow continuously on some systems, with reports of it reaching hundreds of gigabytes—in some cases, up to 500GB.

As the file expanded, Windows incorrectly appeared to be running out of storage despite users having plenty of available disk space.

KB5101650 Includes the Fix

Microsoft addressed the issue in Windows 11 update KB5101650.

Unlike many of the new Windows 11 features introduced in the same update—which are rolling out gradually—the storage fix is available immediately after installation.

Microsoft’s official release notes summarize the change simply:

“[Storage] This update improves disk space usage for the CapabilityAccessManager.db-wal file.”

Existing Large Files May Not Shrink Automatically

Although the bug has been fixed, Microsoft has not confirmed whether systems already affected will automatically reclaim the wasted disk space.

According to reports from users who tested June’s preview update, oversized CapabilityAccessManager.db-wal files remained large even after installing the fix. In those cases, the files only returned to their normal size after being removed manually using the recommended procedure.

How to Check If You’re Affected

After installing KB5101650, users can verify whether the database log file is still consuming excessive storage.

One method is to run the following command in an elevated Command Prompt:

robocopy "C:\ProgramData\Microsoft\Windows\CapabilityAccessManager" "%TEMP%\CAMCheck" /L /B /R:0 /W:0 /BYTES /NP

Alternatively, disk usage utilities such as:

• WizTree
• TreeSize
• WinDirStat

can be used to locate CapabilityAccessManager.db-wal and inspect its size.

If the file measures only a few hundred kilobytes or several megabytes, the system is functioning normally. However, if it still occupies several gigabytes—or even hundreds of gigabytes—it may require manual cleanup using Microsoft’s recommended procedure.

A Welcome Fix for Affected Users

While the storage bug did not affect every Windows 11 installation, it had the potential to waste massive amounts of disk space on impacted systems. With KB5101650, Microsoft has prevented further abnormal growth of the CapabilityAccessManager.db-wal file, although users who experienced the issue should still verify whether existing oversized files need manual attention to fully recover their storage space.