Rufus | Error Code 0xc00305b4

If you are on an older version (like 3.17), update to the latest release. A known bug in version 3.17 specifically caused this error during the "ISO → ESP" creation process on Windows 11, which was fixed in version 3.18. Run as Admin: Right-click the Rufus executable and select Run as Administrator to ensure it has full write permissions. Disable Real-Time Protection: Temporarily turn off your antivirus or Windows Virus & threat protection

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. rufus error code 0xc00305b4

At its core, error 0xc00305b4 signals an . When a user attempts to write an image (such as Windows or Linux) to a USB drive, Rufus requests direct, low-level access to the storage device to write sectors precisely. However, modern versions of Windows (8, 10, and 11) employ a security feature known as Device Guard or Hypervisor-protected Code Integrity (HVCI) . These technologies, while excellent for preventing malware from injecting code into kernel memory, also block legitimate applications from performing direct physical writes to removable media. When Rufus’s driver is denied this permission, the operating system returns the code 0xc00305b4 —a hexadecimal representation of STATUS_ACCESS_VIOLATION . In essence, Windows is telling Rufus, “You do not have the clearance to touch that hardware directly.” If you are on an older version (like 3

Rufus is a popular, free, and open-source software tool that allows users to create bootable USB drives from ISO files. It's widely used for installing operating systems, such as Windows, Linux, and macOS, on computers. However, like any other software, Rufus can encounter errors, and one of the most frustrating ones is the error code 0xc00305b4. However, modern versions of Windows (8, 10, and

While Rufus is a robust tool, this specific error is usually rooted in —such as hardware instability or system-level interference—rather than a flaw in the software itself. Common Causes of Error 0xc00305b4

A failing USB flash drive or a faulty USB port can cause communication delays that trigger a timeout.

Rufus may fail to find or create a logical drive if the USB's current partition table is corrupted or has unassigned drive letters.