Option to change all parts
For example, if I want windows 7 instead of windows 8, I can change it to windows 7 and spend the extra money on a better GPU
ChooseMyPC is predominantly just for generating cookie cutter rigs at each price point for gaming. If you would like in-depth customization based on the original build you can click the ‘pcpartpicker link’ on the page and make your changes from there to suit your needs.
However Windows 8 is all straight upgrades from 7 and is almost the exact same price so I would highly recommend buying it instead.