A hidden Windows 11 log file is quietly swallowing people's hard drives. In the worst case documented so far it grew to 513GB, enough to fill most of a laptop. Most people never see it coming, because Windows buries it under a vague "System files" label.
Windows Latest found one PC where this single log file had ballooned to 513GB, while the page file and hibernation file on the same machine added up to just 29GB. On a healthy computer the same file sits at about 1.6MB. It can keep growing until the drive is completely full, and people have been reporting it for months.
What the file does
Windows keeps a running log of which apps use your camera, microphone, location, and screen. That log should stay tiny. On affected PCs it never gets cleaned up, so Windows writes the same kind of privacy record over and over until it has eaten hundreds of gigabytes. The file is called CapabilityAccessManager.db-wal, and it lives in a protected system folder (C:\ProgramData\Microsoft\Windows\CapabilityAccessManager).
How to check your PC
Checking takes a minute. Open Settings, go to Storage, click "Show more categories," then look at System & Reserved. If that number runs into the hundreds of gigabytes, this bug is worth ruling out. On a healthy PC it should be small.
The file sits in a protected folder, so the safest way to see the exact culprit is a free tool like WizTree, run as an administrator and sorted by size. Don't try to force your way into the folder or change its permissions. On a healthy PC the whole folder is under 4MB.
Microsoft's quiet fix
Microsoft has fixed it, but you'd barely know. The company never issued a public advisory or a known-issue notice. The only acknowledgement was a single line buried in an update's release notes. It reads, "This update improves disk space usage for the CapabilityAccessManager.db-wal file." That's the whole thing.
The fix shipped in the optional KB5095093 preview update on June 23, and Microsoft says it rolls out to everyone in the July update. Microsoft hasn't explained why the file runs wild in the first place, or how the patch handles drives that are already bloated. If your storage has been vanishing for months with no clear reason, this is worth two minutes to rule out.
User reports of the file filling drives, Microsoft KB5095093 release notes
