PSA: if you succumbed to the pestering of those warnings Microsoft has been displaying every time you boot your Windows 10 computer and, um, upgraded to Windows 11, you might have noticed that the amount of storage on your C: drive has been mysteriously diminishing. If so, it might not be your Steam library and/or a bunch of stuff you downloaded and forgot about that are to blame.
Instead, it might be a process called Capability Access Manager, for which Microsoft recently shipped a fix. That fix, included in the optional Windows 11 KB5095093 update, promises to “improve disk space usage for the CapabilityAccessManager.db-wal file.” This is good news, because that file has been displaying an alarming propensity for hoovering storage space.
The easiest fix for the issue is simply to install that update, but if you want to see if you’re affected before you go to the trouble of downloading and installing the fix, you can check the size of the affected file. It’s stored in this directory:
C:\ProgramData\Microsoft\Windows\CapabilityAccessManager\
On a system without the problem, CapabilityAccessManager.db-wal is a few MB in size. On affected systems, users have reported it growing to several hundred GB.
You can try simply opening up a command prompt and having a look at the directory in question, but you might find that you are denied access, even if you run the command prompt with administrator access. This is annoying. Hats off, then, to a site called Windows Latest provides a couple of alternative approaches, as well as a comprehensive explanation of what the file actually is.
First, the alternative checks. If you have a disk space analyzer like TreeSize, you can use that—run a disk scan and then drill down into the above directory to see what’s there. This is probably the easiest method, especially since TreeSize is free and generally a useful little program to have around to keep an eye on what’s taking up space on your drive(s). This is the approach I’d use, for what it’s worth. But if you don’t want to download anything, you can return to the command prompt and use robocopy—which has a handy backup mode that “overrides file and folder permission settings (ACLs), which might otherwise block access access”—to copy the file information to a dummy directory:
robocopy "C:\ProgramData\Microsoft\Windows\CapabilityAccessManager" "%TEMP%\CAMCheck" /L /B /R:0 /W:0 /BYTES /NP
This will provide a list of files; look for CapabilityAccessManager.db-wal and check its size. File sizes here are provided in bytes, so if you’re at seven figures, you’re doing fine. If you’re at several more figures, you might have a problem. Again, all credit to Windows Latest for this idea.
And finally, if you’re wondering what the file actually is, it’s basically a write-ahead log of requests made by applications for access to privacy-sensitive system components—things like the camera and microphone. It appears that for whatever reason, the log is ballooning far beyond a reasonable size. Windows Latest speculates that the log isn’t getting merged back into the main database properly, which seems reasonable, but until Microsoft actually issues some sort of explanation as to what’s gone wrong, all users can do is a) check if they’re affected and b) install the update if necessary.
