Generally when you install Windows 7 on your PC, we use the DVD drive for booting set up files. But not all laptops and netbooks come with DVD drives, so an ideal way would be to boot from USB drives. Setup from USB is a freeware tool which would convert your USB flash drive into Windows Vista or Windows 7 bootable setup disk. You can make your USB drive as bootable and setup Windows Vista or Windows 7 on any computer that supports booting from USB.
The step by step wizard interface is pretty simple and you need to select the location where the Windows set up files are located.
In the next step select the USB drive for creating a bootable disk. Please make sure that the USB drive has a minimum of 4GB space for creating the bootable disk. Further, keep a back up of any data available in the drive as the set up might delete and format the existing files.
Setup from USB is the best option for netbooks which does not come with a DVD drive for booting Windows.