windows uses hardware, but it does not control hardware (ie, win7 32bit will install and run fine on 16GB of ram, but the OS is limited to recognizing 3.xGB of it). You can OC and put as much ram in your computer as you want. Win7 OEM, Retail, or from a school or MAR program are all the same stuff, just with different licence agreements. Basically Retail follows you, OEM/MAR follows the computer, and School licences can be either depending on the school you go to and their deal with MS. No matter the case you can install it on a computer and use it. For technical hardware limitations I would check win7 website.