Windows 11 C Drive Full: CapabilityAccessManager.db-wal Huge File

What is happening?

Some Windows 11 users find that System & reserved storage becomes unusually large and the C drive loses tens or even hundreds of gigabytes. One possible cause is a very large file at:

C:\ProgramData\Microsoft\Windows\CapabilityAccessManager\CapabilityAccessManager.db-wal

This guide shows how to check the file size and follow a safe troubleshooting order without deleting protected Windows folders.

Checks shown in the video

1. Open winver and record the Windows version and OS build.
2. Check whether the PC uses x64 or ARM64.
3. Check the C drive free space.
4. Open Settings → System → Storage → System & reserved.
5. Check the exact size of CapabilityAccessManager.db-wal.
6. Install the latest applicable Windows update.
7. Restart Windows.
8. Use Windows Temporary files cleanup.

PowerShell file-size check

Open PowerShell and run:

Get-Item "C:\ProgramData\Microsoft\Windows\CapabilityAccessManager\CapabilityAccessManager.db-wal" -ErrorAction SilentlyContinue | Select-Object FullName,@{Name="SizeGB";Expression={[math]::Round($_.Length/1GB,2)}}

If no result appears, the file may not exist at that path or PowerShell may not have access to it.

Windows update method

Microsoft documents that the June 23, 2026 preview update KB5095093 improves disk-space usage for CapabilityAccessManager.db-wal on applicable Windows 11 version 24H2 and 25H2 systems.

Use Settings → Windows Update first. For manual installation, download only from the Microsoft Update Catalog and select the package matching your Windows version and architecture.

Read Microsoft’s KB5095093 release notes

Example command shown in the video:

wusa "C:\Users\YourName\Downloads\windows11-kb5095093.msu" /quiet /norestart

Replace the example filename with the exact downloaded MSU filename. Do not run the command unless the package matches your system.

Restart command

shutdown /r /t 0

Save all open work before running this command because Windows restarts immediately.

Safe troubleshooting order

1. Check Windows version and build.
2. Check system architecture.
3. Check C drive free space.
4. Check System & reserved storage.
5. Measure the db-wal file.
6. Install the latest applicable Windows update.
7. Restart the computer.
8. Use Temporary files cleanup.
9. Check the C drive and db-wal file size again.

Disclaimer

This guide is for educational and troubleshooting purposes. Back up important files before system repair work. Download Windows updates only from Microsoft and verify that every package matches your Windows version and architecture.