Disclaimer: I'm not an expert on this, but I know a couple things about Windows in this case.
I installed a full version downloaded from Microsoft, and then installed the key bought from newegg.com. An OEM version probably won't install in a VM because it's limited to specific hardware from that vendor, usually in groups of 20 or 50 systems per OEM CD, and the inside of a VM is not going to match.
I posted here because I heard that Microsoft released some cheap versions of Windows for low-income countries where nobody can afford the American license fee, and the way they protected themselves is by blocking out English as a language choice. Meaning, not only is it not included but they've taken measures to ensure that it can't be installed. If you have one of these versions, then that's probably the problem.