There have been a couple of USB Boot methods to install Windows from a thumb drive.  Some are better than others, but most of them have normally required that you be somewhat savvy with the keyboard.  I recently came across a tool called WinToFlash, which basically cuts out any need to prepare your USB thumb drive like the other software I’ve seen.  You simply format the drive, load the install image, and you’re all set.

The beauty of this is quite obvious.  You don’t have to worry about losing your discs (my main concern), you don’t have to worry about scratching them, and you can carry a thumb drive on your key chain if you wanted to.  This software supports Windows 2003, Windows XP, Windows Vista, and Windows 7.  You can either supply a retail disk, a burned copy, or you can extract a downloaded image file to your hard drive and use that directory for the source.  It’s very simple and can end up saving you money and time in the long run.  I highly recommend setting up one of these bad boys for a rainy day.  You never know when you’ll need it.

You can download this app by clicking here, the software is fairly self explanatory.  NOTE:  I did run into an issue with a thumb drive that was not formatted to begin with.  WinToFlash told me the drive “could not be locked”.  I solved this issue simply by doing a manual format from My Computer, by right clicking the drive, selecting “format”, and performing a “quick format”.

The WinToFlash Homepage
Alternative USB Windows Boot Method