If your Windows 11 drive has been filling up for no clear reason, you are not imagining it. A confirmed Windows 11 bug let a single hidden system file grow without limit, quietly swallowing tens of gigabytes of disk space on affected machines. Microsoft has now shipped a fix. Here is exactly what happened, how to check whether your PC is affected, and how to get your space back.
What is the CapabilityAccessManager.db-wal bug?
The culprit is a file named CapabilityAccessManager.db-wal. It belongs to the Capability Access Manager, the part of Windows 11 that keeps a record of which apps have accessed sensitive resources such as your camera, microphone, and location.
The .db-wal extension marks it as a write-ahead log: a temporary companion file to a small SQLite database. By design it fills up during normal use and then flushes its contents back into the main database roughly once a month, staying small the rest of the time.
The bug broke that cycle. In certain cases the flush never happened, so the file kept growing and growing without ever being emptied. Instead of a few megabytes, it swelled into the tens of gigabytes.
How big did the file get?
Reports varied a lot depending on the machine and how long the bug had been running. According to TechRadar and Neowin, affected users described CapabilityAccessManager.db-wal growing from its normal tiny footprint to anywhere between roughly 25 GB and 60 to 100 GB. Some users cited sizes approaching 200 GB.
On a laptop with a modest 256 GB SSD, that is enough to fill the drive completely and bring the whole system to a crawl. The frustrating part was that the space seemed to vanish with no visible cause, since the file sits deep in the Windows system folder where most people never look.
How to tell if you are affected
The tell-tale sign is simple: your free space keeps dropping even though you have not added large files, programs, or games. To confirm it is this specific bug rather than something else:
- Download a free disk-usage scanner such as WizTree or TreeSize Free. Both list every file on a drive sorted by size.
- Scan your system drive (usually C:).
- Look near the top of the list for a file called CapabilityAccessManager.db-wal. If it is showing tens of gigabytes, that is the bug.
If the file is a few megabytes or does not appear at all, your disk-space problem has another cause. Our guide to what a hard drive is and how storage fills up can help you track down other space hogs.
How to fix the Windows 11 disk space bug
The clean, supported fix is an official Microsoft update, not a manual file deletion.
Microsoft released update KB5095093 on 29 June 2026. Its changelog entry states, word for word: "This update improves disk space usage for the CapabilityAccessManager.db-wal file." Installing it lets Windows correct the flushing behaviour and reclaim the wasted space.
To install it:
- Open Settings.
- Go to Windows Update.
- Click Check for updates.
- Install KB5095093 when it appears, then restart your PC.
- After the restart, re-scan the drive and confirm your free space has recovered.
If the update does not show up immediately, Windows sometimes staggers its rollout. Checking again after a day, and making sure your PC is not paused on updates, usually resolves it.
A word of caution on manual deletion
You may see suggestions to simply delete CapabilityAccessManager.db-wal by hand. It is safer not to. This is a live system file located in the Windows system directory, and deleting files there carelessly can cause other problems. The low-risk path is to let KB5095093 through Windows Update handle it. Leave manual intervention to advanced users who fully understand what they are doing and have a backup first.
Recover files if a full disk caused data loss
Why a full disk is more than an annoyance
A drive that fills to 100 percent is not just inconvenient. Windows needs free space to work: to write temporary files, apply updates, and save your open documents. When space runs out, you can see failed updates, apps crashing mid-save, and a general slowdown. That is precisely the kind of situation where files get corrupted or a save is lost.
This is why fixing the bug and keeping a backup go hand in hand. If you are not already following a backup routine, our 3-2-1 backup strategy guide walks through a simple setup that protects your files even when the system misbehaves.
Prevention going forward
- Keep Windows Update current. This bug was fixed by an update. Staying up to date is the single most reliable way to receive fixes like this one promptly.
- Watch your free space. If your available storage drops sharply without explanation, run a disk-usage scanner early rather than waiting for the drive to fill.
- Consider your drive type and size. Small SSDs fill fastest and feel the impact hardest. If you are weighing an upgrade, our SSD vs HDD comparison covers the trade-offs.
- Back up regularly. A current backup turns a full-disk emergency into a minor inconvenience.
The bottom line
The Windows 11 disk space bug came down to one file, CapabilityAccessManager.db-wal, that was supposed to shrink each month but kept growing instead. Reported sizes ran from about 25 GB to as much as 200 GB according to users cited by TechRadar and Neowin. The fix is straightforward: install KB5095093, the update Microsoft released on 29 June 2026 specifically to improve disk space usage for that file, then confirm your space is back. Skip the risky manual deletions and let Windows Update do the work.
Related guides
- Hard drive failure: signs, diagnosis, and what to do
- The 3-2-1 backup strategy explained
- SSD vs HDD: which drive is right for you
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