* First, you’ll need the DiskPart utility on the system you will use to
prep the thumb drive. This is a free disk partitioning utility that is
likely already installed on your Windows system. If not, you can download
DiskPart here.
* Launch the DiskPart utility by typing diskpart at the Start Menu.
* Then run the list disk command to check the status of your drive.
Video
Dennis Chung, an IT Pro Evangelist at Microsoft, demonstrates how easy
it is to prepare a USB thumb drive and use it to install Windows 7.
* Now run select disk 1 where the "1" is actually the corresponding
number of your USB drive.
* Run clean.
* Once the thumb drive is clean, you can run create partition primary.
* Now make the partition active by entering active
* Then you need to set up the file system as Fat32 by running format fs=
fat32 quick (quick, of course, specifies that you want to perform a quick
format to speed up the process).
* Entering the assign command gives the USB drive a drive letter, making
it easy to access from Windows Explorer
* Then you can copy everything from the Windows 7 installation DVD onto
the USB key (a simple drag and drop will do).
* Now you can insert the thumb drive into the system you want to install
Windows 7 onto and boot the system. The installation will now proceed as
usual—but faster.