Microsoft has confirmed that a serious Windows 11 bug is currently eating up to 500GB of storage on affected PCs running Windows 11 versions 24H2 and 25H2, leaving users seriously short of space and in extreme cases risking eventual system failure.

What Is The Windows 11 Storage Bug?

Users have reported the bug as far back as May 2025 , but Microsoft only revealed a fix on June 29—which won’t roll out automatically until July 14. However, affected users, especially those with smaller drives (256GB to 500GB), may need to address it manually now to avoid system failures when the available space hits zero. Running simple disk cleanup tools won’t recover your space and the file could keep growing indefinitely.

Windows 11 Disk Space Bug: Am I Affected?

It’s easy to check if you’re affected: Just open Settings, System and then Storage. Next, click on ”Show more categories” and look for “System & reserved.” If the “System files” category contains more than around 100GB you’re likely to be affected.

The storage bug affects a hidden file called CapabilityAccessManager.db-wal that lives deep in your “%ProgramData%\Microsoft\Windows\CapabilityAccessManager” folder. Windows 11 makes it very difficult for you to access this file directly, but you can work around this by using a free tool like WizTree to search for the file on your hard drive and reveal its size. If the file is ballooning into gigabytes, you’re almost certainly affected.

How To Fix The Windows 11 Storage Bug

Microsoft has issued a downloadable fix as part of a recent optional update, KB5095093 , but note that this patch also enables a selection of Windows 11 feature previews which may affect your PC in other ways, so be sure to read the documentation before proceeding. For example, it causes issues for some specific third-party app integrations with Microsoft Office.

You can install the update right now by going to Settings, then Windows Update, Advanced Options and selecting Optional Updates. From here you can select the June 2026 preview update.

A word of warning: don’t be tempted to try to delete the CapabilityAccessManager.db -wal unless you know what you’re doing. Multiple users confirmed that doing so can break WiFi and screen capture functionality.

If you’re in no immediate danger of running out of disk space, you may be better off monitoring the situation and waiting a few days. Microsoft will be pushing an automatic fix to affected users in the forthcoming July 14 “Patch Tuesday” update.