If you bought the boxed version of Windows 8 Pro, there were only two versions available. One is Windows 8 Pro Upgrade and is used to upgrade from Windows 8 to Windows 8 Pro. The second version is the OEM version. In Windows 8 the OEM version can be installed on another PC that you own but if you sell or transfer the PC with the OS then it is locked to that PC for the new owner. This is called the "personal use license" for the OEM version and is only available for Windows 8. The PUL does not apply to an OEM version that came pre-installed on a PC from a vendor. Windows 8.1 is now offered in a OEM and Retail version and does not have the PUL.
Jim
Makes sense. Two more questions which are not clear to me. How do I determine if I have the upgrade version of Windows 8 Pro or the OEM version (I did a clean install of Win 8 Pro, not an upgrade from Windows 8, so it would have to be an OEM version)?
And if I have the OEM version and I install it on a new PC I build, will the upgrade to Windows 8.1 be available to me in the Windows Store?
Thanks for the information, things certainly are much more convoluted since the XP days!