Hi guyz... let say if i wanna install Windows Server 2008 Standard Edition into a server.. then i install 3 virtual machines into that server with Win Server 2008 Std Edition also.. do i need edition 3 license for these 3 OS also?

It's on the same machine physically, so you don't need additional license.

Wrong. You need a separate license. Confirmed that with Microsoft regarding my Vista license.

Depends on where you get the media in the first place. If it's from MSDN and you're using the VPC for development purposes, you won't need additional licences. But if you're deploying that for production or it's not MSDN media, then you need the licence.

I have a legal Vista license in my host computer. Installed another inside a virtual machine on the same host computer. It will run for a while then blocked. Called Microsoft and was told I need extra license.

So my guess is, once a copy is being used, Microsoft probably keep a log of that and will prevent a 2nd copy from being used.

But for XP, no such problem.