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).
The error in Rufus on Windows 7 is almost always a phantom lock left behind by Windows Explorer or a legacy driver. The most reliable fix is to end the explorer.exe process before running Rufus. If that fails, a DiskPart clean will reset the drive completely. rufus access to device denied windows 7
Warning: clean will erase all data on the selected disk. Rufus uses the Windows CreateFile API with GENERIC_WRITE
Windows 7 was the prime era for intrusive antivirus software. Real-time file system filters often intercept Rufus’s write requests, mistaking them for malicious activity. The most reliable fix is to end the explorer
Instead of using Windows format:
Rufus is a popular tool for creating bootable USB drives. However, some users may encounter an "Access to device denied" error when trying to use Rufus on a Windows 7 system. This error occurs when Rufus is unable to access the USB device due to permissions issues.