To the best of my knowledge that was true for 7 but not for 8
if you bought the OEM license yourself and did the installation. If you have a machine that came with win8, it's not transferable.
To quote myself in
http://www.tomshardware.com/forum/16-73-windows-guide-last-updated-2013 ,
The licensing model has changed in Windows 8. The "Full Retail" version is no more, and if you buy a non-upgrade copy to install on bare metal you will be buying the OEM / System Builder version and installing it as a "Personal Use" license.
The biggest difference is that the Windows 8 version does not include Microsoft support.
Despite being called an OEM license, the license is different from previous OEM licenses in that the "Personal Use"...