Context: Unlike previous versions of Windows, Windows 8 was distributed at retail in "Upgrade" licenses only, which require an existing version of Windows to install. The "full version software" SKU, which was more expensive but could be installed on computers without an eligible OS or none at all, was discontinued. In lieu of full version, a specialized "System Builder" SKU was introduced. The "System Builder" SKU replaced the original equipment manufacturer (OEM) SKU, which was only allowed to be used on PCs meant for resale, but added a "Personal Use License" exemption that officially allowed its purchase and personal use by users on homebuilt computers.

Question: What restrictions do Windows upgrade licenses have?
Answer: require an existing version of Windows to install

Question: What did Windows offer in place of a full version of the software?
Answer: specialized "System Builder" SKU

Question: What did the System Builder SKU take the place of?
Answer: (OEM) SKU

Question: What does OEM stand for?
Answer: original equipment manufacturer

Question: What did the Personal Use License allow?
Answer: purchase and personal use by users on homebuilt computers

Question: What restrictions don't Windows upgrade licenses have?
Answer: Unanswerable

Question: What did Windows offer in place of a preview version of the software?
Answer: Unanswerable

Question: What did the System Builder SUK take the place of?
Answer: Unanswerable

Question: What does OME stand for
Answer: Unanswerable

Question: What did the Personal Use License disallow?
Answer: Unanswerable