OEM installation media has nothing to do with OEM computer manufacturers per se. The OEM license is just a different packaging for windows that is targeted to small scale computer manufacturers. OEM installs come only with an install media and no support from MS, OEMs are expected (obliged actually) to provide support and instructions to their customers as part of the EULA.
OEM builder such as Dell will use volume licensing deals on their products and deliver their computers with a preinstalled 'added value' software which most people consider as borderline harmful since they usually do nothing more than consume resources and cause trouble. This is why you see people with store bought computers that have 100+ processes running straight out of the box 
when you build a computer you are an OEM computer manufacturer for sure. just trying to make it clear between computer manufacturers such as del, gatewate... some here call them brand name computer manufactures and other people who also build computers as a business but wont install anything additional.
semp
a little bit of a difference.
