For advanced users, you can use the built-in tool in Windows to prepare a drive manually: Open Command Prompt as Administrator. Type diskpart followed by list disk . Select your USB (e.g., select disk 1 ). Run clean , then create partition primary . Format it using format fs=ntfs quick . Mount your ISO and copy all files to the USB. Important Considerations
Here is the complete guide on how to use the . media creation tool for windows 8.1