Netbooks do not include optical drives. So, how can netbook owners install Windows 7 from a DVD? The simple answer is from an external DVD drive connected to the netbook via USB. However, most people probably don't have an external DVD drive and don't want to purchase one.

Microsoft's newly introduced solution for installing Windows 7 on a netbook is to purchase it from their online store, download the ISO image file and using...

Microsoft's Official USB/DVD Download Tool Helps you Upgrade Netbooks to Windows 7

You need to supply a USB flash drive with at least 4GB of available space. The tool deletes anything on the flash drive and creates a bootable Windows 7 installation drive.

You can find and download the tool from the Microsoft online store...

Windows 7 USB/DVD Download Tool