If you want to burn Windows 8 to USB the activation key must be valid because you will need it during the process of the installation.

If you want to burn Windows 7 to USB you need to download Windows 7 ISO file with the Windows activation key. However, the only requirement to burn ISO to USB with WintoUSB is the ISO file of the Windows you want to burn to your USB. However, in this guide, you will get to know how to use WintoUSBīoth Rufus and WintoUSB can be used to burn Windows OS to removable such as USB, DVD/CD, Pendrive, floppy disc, etc and it supports all Windows OS. WintoUSB is a light portable tool that rips the Windows OS installer and burns it into a removable of your choice once the remove meets up with the minimum requirement to use Win to USB tool. The Win to USB tool works in a similar way to use Rufus to burn Windows to USB or burn Windows to DVD. WintoUSB is a portable tool to burn Windows ISO to USB or DVD to create a bootable removable device to install Windows OS with a USB or DVD.

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