1. You can't use the OEM license with retail installation media.
2. You don't get OEM installation media because the license is tied to the hardware.
3. The OEM recovery media can't be restored to different hardware.
4. The OEM license key can't be used to install a retail Windows install on a different computer.
At some low number of customers, the more complex you make your licensing, the fewer people buy and the fewer people renew, and since piracy is roughly zero anyway, you make your licensing simple.
Then something magical happens somewhere in the middle, where either piracy becomes scarier or your customers are more locked into your ecosystem. Then the more complex you make your licensing, for some reason the more profit you can get out of your customers. It must be this way, otherwise we'd have no way to account for MS/Oracle/IBM.
I wonder where the crossover points on the chart are.
* How much piracy do you take before you make your licensing a nightmare?
* How "enterprise" do you have to go before you stop worrying that making your software a massive pain to install and upgrade won't bleed your customers away?
I've done it once in the past and it wasn't super complicated. It looks like it might be harder to find the oembios files now, but I bet you can still accomplish this if you're determined.
https://superuser.com/questions/539714/windows-all-oem-activ... has some details that could get your pointed in the right direction