As far as I know, it is "per running instance". Since you're running your virutal window session on an windows machine, then you need two licenses. If you make multiple copies of the second environment, you only need additional licenses IF you plan to run multiple instances at one time.

IMO, you'd be better off runnin your base OS as linux and then use your other license for a virtual environment. However, since OEM licenses typically can't be transfered... I'm not sure how that'd work out since you're technically on different hardware. You're running on virtual hardware...

Man... confusing subject.

IMO- If you're running them at work... get the licenses. If you're running them at home... who cares!

http://www.microsoft.com/presspass/f...licensing.mspx