Limitation of virtual machine (Hyper-V) on Windows 8

Question

We can install 2 vm on windows server 2012 enterprise edition and unlimited vm on windows server 2012 datacenter. What about windows 8?

Answer 1

Licenses are assigned to the physical machine, and virtualization rights are assigned according to the license assigned.  So if you are running Windows 8, you can assign a Windows Server 2012 Standard license to the physical machine (nothing is 'installed';
it's simply a matter of keeping track that that license is assigned to that physical machine).  The Windows Server 2012 Standard license grants you the right to run up to two Windows Server Standard virtual operating system environments (VOSE) simultaneously. 
There is no limit to the number of VMs you can create.  The license is for the number of simultaneously running VOSE.
The activation key is not a license key.  The activation key is simply used to activate an instance of the operating system.
If you want to run a down-level version of the client operating system, you will need another license.  Again, the license is assigned to the physical machine.  If you upgraded from XP or Windows 7, you are still using the 'original' license; it
is in an upgraded state now.  The client license gives you the right to run a single instance of the operating system.  To run a second instance of the client OS, you would need another license and assign it to the same physical machine.  (Caution: 
I have not dealt with client licensing as much as server licensing).
In all licensing question cases, it is highly recommended that you contact your Microsoft licensing specialist to get the proper answers.  Answers found on TechNet forums is generally based on opinion and experience, but it is not legal advice. 
Go to www.microsoft.com/licensing to find a local, toll-free number to call to talk with a licensing specialist.
tim