@rtp
First I backed up my Windows 7 Starter recovery using one of my PC's DVDRW with a USB adapter, then I downloaded Windows 8 (Never buy from stores, they are just SH*T. Then I grabbed my 8GB USB Flash drive, and used
Windows 7 USB/DVD download tool and I just selected the ISO image I downloaded and it transfers it to the USB Drive.
After that, you restart and press F11/12 (Same button on our laptops) and the boot menu will appear, then you just select the USB Drive and go on from there.
But do note that the S100's resolution is 1280x600, which is below the Windows 8 UI reqs, Metro apps will not open since they need 1280x760. So what you do is, you go to regedit >HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Class{4d36e968-e325-11ce-bfc1-08002be10318}\0001 and set Display1_DownScalingSupported value to 1 and restart.
Your resolution will change, and run at higher (A bit blury, but it's tolerable)