Dear All,I plan to install Windows Server 2008 Datacenter and user Virtualization.But for the Licence, could give me some precision.How many licence do i need for Windows Server 2008 with 4 virtual machine ?We are 25 in my company. If i buy 5 user licence, will it work with 25 users ?Thanks a lot for your answer ?Fly

This is not an easy question to answer: You would probably want to run other Microsoft products like Exchange Server, SQL Server, ISA Server, Sharepointin your virtualized Windows Server 2008 machines, for which you may need to purchase licenses and/or additional Client Access Licenses (CALs); The number of physical processors in your Virtual host may have an impact on licensing costs; Your future virtualization expansion plans might make you decide to place a more scalable licensing solution. Luckily Microsoft provides two Virtualization Calculators you can use. These calculators pinpoint exactly from which licensing solution, based on Windows Server Standard, Windows Server Enterprise or Windows Server Datacenter you would benefit the most. Note:Although these calculators still mention Virtual Server as virtualization method, the same Windows licensing information applies to Hyper-V virtualization. When you need further assistance I recommend you contact a Microsoft Partner with the Licensing Solutions competency. Correctly licensing a Windows environment is not easily accomplished.

Windows Server 2008 Datacenter Edition provides for an unlimited number of virtual instances running on the host to which you assign the Datacenter license. The Datacenter license itself is purchased for the number of processors in the physical host. Other Editions of Windows Server 2008 provide fewer instances and have some other restrictions when you reach the maximum. The server provides services to clients. You say that you have 25 in your company. For licensing purposes, you need to purchase one Windows Server Client Access License (CAL) for each system making use of the services provided by Windows Server. So, in your case, you would require 25 Windows Server CALs. If you were to purchase and install a second physical server running another instance of Windows Server 2008, the number of CALs required would not change because a CAL gives you access to any 2008 server. Sander also provided very good information about other products you may want to run. http://www.microsoft.com/licensing/default.mspxprovides a good place to start when you need licensing questions answered. And, that will be more authoritative than anything you get from this user community. tgc

Hello, Thanks Tim and Sander for the information sharing. If you need more assistanceabout licence questions, you could call 1-800-426-9400 (select option 4), Monday through Friday, 6:00 A.M. to 5:30 P.M. (PST) to speak directly to a Microsoft licensing specialist. Worldwide customers can use the Guide to Worldwide Microsoft Licensing Sites http://www.microsoft.com/licensing/index/worldwide.asp to find contact information in their locations. Thanks.