As the form factor of the laptops (read NetBooks) reduces in size it comes with certain drawbacks. One of the most prominent is the lack of an optical drive, for example, CD or DVD Drive. Of course, you can plug-in an external optical drive but that’s certainly an inconvenience. Instead why not make use of the USB ports that comes with those slim-line notebooks (NetBooks) and install software using, let’s say, an USB Thumb Drive.
Read from this detailed article at DemoGeek.com to learn how to prepare a USB Thumb Drive to install Windows 7 Beta from an USB Thumb Drive. It’s a 10 step process but the steps are pretty simple and well explained.