Surfing around this morning, I found an interesting blog article: Installing Windows 7 From USB Drive 3 Steps Easy Process. Basically, this article shows how to prepare a USB stick from which you can install Windows 7. This is specifically useful for Netbooks or other systems that come without a DVD drive. This method uses the UltraISO trial package. You do need a big USB stick, 4gb or more and make sure you have the latest version of UntrlISO.