Step 1 : Download  Windows 7 USB/DVD Download Tool
This is available for free from Microsoft. This tool works with Windows 7, 8 and Window 8.1. You can run this tool on virtually any version of Windows.


Step 2 : Select the Source file.Source File is ISO file . Click Next.




Step 3 : Select USB device. You are given the option to either burn to a DVD or create a USB device.


Step 4 : Choose your USB device. Make sure that your flash drive is connected correctly. You will need at least 4GB space on your flash drive to copy over the Windows installation.

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Choose your USB device.

Step 5 :Wait while program works. The program will format the USB drive to boot correctly, then copy the ISO file onto the drive.