Techgage.com posted a guide about using a Thumb Drive to Install Windows 7
>> Using a Thumb Drive to Install Windows 7
Microsoft may be selling Windows 7 exclusively on DVD's, but did you realize that it takes very little effort to create a bootable thumb drive and install from that? We're taking a look at two popular methods of accomplishing this, and as you'll see, it couldn't be easier to install Microsoft's latest OS onto a PC with no DVD-ROM. It's faster, too!
>> Using a Thumb Drive to Install Windows 7