Windows 7 automatically mounts removable drives and may lock the volume for indexing, autorun scanning, or file system checking. Additionally, Group Policies can disable write access to removable storage entirely.
Rufus uses the Windows CreateFile API with GENERIC_WRITE and FILE_SHARE_READ flags to open physical drives ( \\.\PhysicalDriveX ). If another process holds a lock or if security policies block direct write access, the API returns ERROR_ACCESS_DENIED (5). rufus access to device denied windows 7
If a program is actively using the USB drive, Rufus cannot lock it for formatting. Windows 7 automatically mounts removable drives and may