Note : This article was written when Windows 7 was still in BETA 1, changes might occur later to the product once it is RTM.
Update on 24/Oct/2009 : Check my new article Using The Windows 7 USB/DVD Download Tool. Now you can use a tool to create a bootable USB Device.
First we will need to mount the content of the Windows 7 DVD ( or the ISO file ) to the external Flash Memory. Open Command Prompt ( cmd ) and write the following commands: