Microsoft has acknowledged an issue following the installation of the Windows 11 2003 Update (Windows 11 24H2), where users encounter an unexpected 8.63 GB of undeletable data. The problem is attributed to a malfunction in the Windows Disk Cleanup tool, which is causing a reporting error rather than an actual loss of recoverable disk space. After running Disk Cleanup, it may inaccurately report an amount of space still available for cleanup in the 'Windows Update Cleanup' category, despite some files being cleaned up correctly during the initial run. Microsoft is working on a resolution for this issue.