Apple says you can run up to 2 virtualized copies of OS X 10.7 Lion, as long as you’re doing it on a Mac with a paid-for copy of the operating system. A Windows host would violate Apple's EULA, and we don't advise how to bypass legal restrictions. Sorry.
In 2007, Apple first extended this capability in Mac OS X Server 10.5 (server only):
The 2007 Mac OS X 10.5 Server EULA] permits OS X Server to run in a virtual machine (VM) as long as each VM is stocked with a different license and the physical system is Apple-made. The new rules don't apply to the client edition of Apple's operating system, which is still barred from being virtualized.
OS X Lion (10.7) EULA released in 2011 says that users can run up to two additional instances of OS X Lion on their same machine without a need for extra licenses. From the 10.7 EULA:
(iii) to install, use and run up to two (2) additional copies or instances of the Apple Software within virtual operating system environments on each Mac Computer you own or control that is already running the Apple Software.
