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Can you help me with my software licensing question?

I'm hoping that someone can clear up a question regarding the ever confusing Microsoft client access licensing.

Reading this page, would suggest that if you bought a client or device CAL and set the licensing mode on the server to 'per client or device' (as opposed to 'per server'), then each CAL would allow that many users or devices to connect to all the Microsoft servers** on the network.

For example, say we have a network with 100 users, 100 clients, and 10 Windows servers, but we only have 50 user CALs (for argument's sake - because I know that isn't enough CALs).

Now suppose I purchased a new server, with a server operating system with another 50 user CALs, does this give all 100 of our users access to all 11 of our Windows servers?

The link above suggests that is the case, however, why is it then, that when I attempt to buy a server with an OEM version of a server operating system, that I can't buy it without CALs?

What I'm actually looking at, is buying a Hyper-V server with Windows Server 2008 enterprise (to allow me to run 4 OS instances), however, I can't seem to purchase Server 2008 enterprise with any less than 25 CALs. Why is this?

** = To the type of server the CALs belong to (e.g. Server 2003 or Server 2008 - but not both)

marked as duplicate by Iain Jan 27 '12 at 17:27

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You are reading correctly... If you choose per user/per device, they will be able to access all 10 of your Windows servers, and you would need as many CALs as you have users or devices (per user makes sense if you have users that may be accessing the servers from several different devices, per device makes sense in an environment where you have many users accessing the servers from a few devices, such as a company with shift work).

I ran over to http://www.cdw.com and typed in "server 2008 enterprise", and the first few results didn't appear to come with CALs (which I believe is what you are looking for). Your best bet is to directly call a reseller such as CDW (and they can tell you what licenses are available), or call the Microsoft licensing hotline (800) 426-9400, where they have people trained on the ins and outs of licensing.


Microsoft's Open License program allows purchase of software without CAL's. The Box & OEM version's come with CAL's because thats how MS sells them. If you have more then a couple of a computers its better to go with the Open License program.

  • 1
    +1 for open license over OEM. The "discount" an OEM version of an OS gives you over an open license version is quickly lost when you have to "re-buy" the operating system because you elect to disuse a server with an OEM license attached when replacing a server computer. – Evan Anderson Jul 4 '09 at 20:41

I think that OEM licenses come with CALs because Microsoft has a HUGE amount of influence over the way that OEM licenses are handled. They have probably simply dictated that you can't sell an OEM server license without CALs and the OEMs have no choice. That said, I have found that Volume Licensing is often cheaper then OEM licensing and gives you much more flexibility. I strongly suggest buying your severs without software and using Volume Licenses for all your Microsoft products.

  • Thanks everyone. That has certainly cleared things up. I've never considered volume licensing before, however I'm now looking into it. Thanks again. – Bryan Jul 5 '09 at 10:43

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