Antivirus software or Windows Defender "Real-time protection" may lock the drive to scan it, preventing Rufus from completing its write operation.
Rufus error code 0xc00305b4 is frustrating because it halts the bootable USB creation process without a clear human-readable message. However, as you have learned, the error is almost always related to the state of your USB drive, Windows write permissions, or USB controller drivers — not a bug in Rufus itself. rufus error code 0xc00305b4
This is the single most reliable solution. Using Windows’ built-in DiskPart tool, you will completely wipe the USB drive, removing hidden partitions, corrupted boot sectors, and file system errors. This is the single most reliable solution
Larger ISOs (over 4 GB) use more complex file writing patterns and can expose timing issues with your USB controller or driver that smaller ISOs do not trigger. removing hidden partitions