Can someone please help me understand the licensing I need? I have a Windows 2008 R2 Standard server. I would like it to host 4 (for now) virtual Windows 7 Pro o/s that 4 people would connect to with their remote windows 7 Pro laptops (or I suppose any device like iPad or something)... using ... RDP? I don't know that part yet.  If RDP, I'll have to use a public IP and dedicated port to route to each virtual machine.

I found a Microsoft document titled "Deploying Personal Virtual Desktops by Using Remote Desktop Web Access Step-by-Step Guide".  I tried following it as best I could.  It has me install a bunch of RDS roles, it uses separate servers, I only have one server available so I put them all on my one 2008 R2 server.  In the end, it has me using Hyper-V manager on the server, and the Windows 7's are virtual machines.  Seems like I could have skipped all the effort with RDS stuff and just installed hyper-v role and virtual machines.  Maybe I went wrong somewhere?  My Dell rep said to do this, I need to purchase 4 RDS CAL licenses and no Windows 7 licenses, so I did.  RDS CAL license says no key comes with it, its apparently not something I type in the Windows 7 activation screens.  I used an old Windows 7 install CD from a previous dell computer to install the virtual machines.  Now they (win 7's) are asking for a license key to be activated.  That implies I set this up all wrong, or the Dell rep was wrong and I really do need to buy four windows 7 licenses (in order to get keys for them).  Can someone straighten me out?  Am I going about this all wrong, or what licensing piece did I miss and what do I use to fulfill the windows activation requests?  Thanks!

Hi,

Thank you for posting in Windows Server Forum.

From your description it seems that you want to have 4 host windows 7 VM which will be used for your users to use. If you are installing server OS as guest on hyper-v servers then you have to have server standard CALs and RDS cals as well, the benefit here once you get 2012 \ 2012 R2 CALs, you don't have to purchase down grade server CALs, you can access those servers without extra licensing

You do require win XP \ 7 \ 8 client OS licenses
Also if you want to use office then you require Office license to access.
 
For VDA
There are two ways that you are able to connect to your virtual desktop.
1. From a traditional Windows Desktop or Laptop
2.From a Thin Client or Non-Windows OS (this includes iPads and other tablet devices)
 
In the same way, Microsoft provides two licensing options for you to connect to a virtual desktop.

Option 1 Microsoft SA (Software Assurance)
To qualify for Virtual Data Architecture (VDA) , you are required to have current Software Assurance on your Operating System. To achieve this, you need to add the SA within 90 days of your purchase of a computer with a legal OEM copy of Windows 7 Professional. Alternatively you would need to purchase Windows Upgrade licenses with Software Assurance.
If you have current SA on your Windows Desktop i.e. Windows Enterprise the Product Use Rights entitle you to access up to four virtual desktop environments.
Licenses are per device. The SA benefit is not available for Thin Clients.

Option 2 Microsoft VDA (Windows Virtual Desktop Access)
Windows VDA is a device-based subscription that has been designed to help organizations license devices that do not qualify for Windows Client SA (such as thin clients, contractor PCs, etc) to be able to access a virtual desktop.
The VDA license is required for all thin clients regardless of the type of device or Operating System. Windows VDA licenses extend roaming rights for the primary (named) user of a company-owned device covered under Windows VDA.

So according to me if your 4 users are accessing 4 Virtual desktops, still you require 4 VDA licenses as you are accessing Virtual desktops from 10 devices which are not in SA.

In contrast, an RDS CAL is required to log on to the RDS Server for accessing remote applications if you have any installed.

For more information refer below articles.
http://www.virtualizationpractice.com/licensing-vdi-for-microsoft-desktops-is-it-rocket-science-9389/

Hope it helps!

Thanks.