"An access denied error when trying to access the C:\ drive is certainly a bad day for Windows users. The C:\ drive is usually assigned to the first bootable disk partition and is where system files and applications are typically located.
However, for some users running Windows 11 24H2 and 25H2, the C:\ drive became inaccessible, with reports of the issue occurring around the time of the March Patch Tuesday update. There were also reports following the installation of the February 2026 security update."
https://www.theregister.com/2026/03/16/samsung_c_drive_windows/

