It’s inherently difficult to load Windows OS without a CD/DVD drive on a NetPC, which often comes with a “Starter” or low-end version of the Windows OS. In my case (an Asus 900HA), it was the Ubuntu Linux that I was trying to replace with Windows 7. I purchased a 3-license Windows 7 Premium Home version a while back from Microsoft Store. I first had to download the 32-bit .iso file version from Microsoft Store. Then I followed the directions in this website to install the Windows 7 OS without any problem. I just follow the instructions for Windows Vista and Voilia! It worked. To boot from USB thumb drive for Asus NetPC, the trick is the press F2 on the BIOS splash screen then set the Boot Order under HDD menu and select the USB thumb drive to be booted ahead of the original HDD. The author, Damien, came up with a different method for Windows 7 WinToflash. It looked a bit easier with a special software. But I didn’t follow that one as I didn’t see it. A strong endorsement to the website for helping me.