Notice what's in bold type.
This is from the Windows 8.1 EULA, http://www.microsoft.com/en-us/windo...e/default.aspx
How can I use the software? We do not sell our software or your copy of it – we only license it. Under our license, we grant you the right to install and run that one copy on one computer (the licensed computer), for use by one person at a time, but only if you comply with all the terms of this agreement. Typically, this means you can install one copy of the software on a personal computer and then you can use the software on that computer. The software is not licensed to be used as server software or for commercial hosting, so you may not make the software available for simultaneous use by multiple users over a network. For more information on multiple user scenarios and virtualization, see the Additional Terms.
What about updating the software? If you install the software covered by this agreement as an update to your existing operating system software, the update replaces the original software that you are updating
. You do not retain any rights to the original software after you have updated and you may not continue to use it or transfer it in any way.
This agreement governs your rights to use the update software and replaces the agreement for the software from which you updated. After you complete your update, some apps may not migrate or may be incompatible with Windows 8.1 Pro and additional software may be required to play back or record certain types of media, including DVDs.