MS don't seem to have sorted the licensing model, to make it convenient with their OS, I have a copy of Windows 8, that I want to move from one machine to another at some point, and I'm sure it will be non-trivial. Not to mention that I'll loose Windows media centre most likely in the process. Even the install for Windows 8 for me was an incredibly convulted process at the time.
When DRM impinges upon usability, and convenience - it's just a complete pain in the backside.