An unusual bug affecting Windows 11 users on Samsung devices prevents access to the main C: drive, following a February 2026 security update (KB5077181). Users receive an "Access denied" message when trying to launch applications or access files. The issue is linked to a Samsung-specific application, particularly the Galaxy Connect and Galaxy Share Folder applications, which may have broken Access Control Lists in Samsung’s factory image for Windows. Affected devices include various models of the Galaxy Book 4 laptops and certain Samsung Desktop models. Users are advised to remove the affected applications or revert to a recommended version while awaiting an official resolution from Microsoft and Samsung.