Today, organizations are looking to reduce desktop TCO, while improving flexibility and streamlining management. Desktop Virtualization solutions can help you improve the management and flexibility of your desktops. This article will help you understand how to license Windows® for Virtual Desktop scenarios.


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.


In order to clarify, here are some scenarios:



Licensing Solution

Mixed Desktop Hardware: 100 PCs under SA and 100 thin clients (running a minimal OS) 100 Windows® client VMs.

For the 100 PCs covered under SA, no additional licensing is required. Each of the 100 thin clients would need a Windows® Virtual

Desktop Access (VDA) license.

Shift Workers: 100 Thin Client devices throughout the hospital, all accessing Windows 7® Virtual Desktops shared by the 300 nurses

Microsoft® Licensing Required = 100 VDA Licenses (1 per device)


Home Use: 100 Thin Client devices in the office connecting to virtual desktops, 50 of the 100 users also occasionally work from home using their personal home PC’s and/or iPads.

Microsoft® Licensing Required = 100 VDA Licenses for the 100 Thin Clients (Roaming rights)


Roaming Users

300 thin clients throughout the company and only 100 users who roam from station to station.


Windows® VDA is a device–based license so 300 thin clients must be licensed with Windows® VDA. If the devices are PCs covered with

SA, then no additional licensing is required.

Contractor-owned PCs

100 contractors who are working for six months, and we will engage 100 different contractors the other six months of the year.

100 Windows® VDA licenses are required for the contractors to access the VDI environment. You can transfer the Windows® VDA licenses to the second set of contractors after a period of 90 days of first assignment.


Other things to note about the Microsoft® VDA license are:

  • If the device you are connecting from is licensed with SA or VDA you do not need to purchase any additional Windows® OS license for the virtual desktop.
  • There is no limit to the movement between servers and storage. This allows you to create virtual drives for training, testing or other specific scenarios.
  • A single Windows® VDA license allows concurrent access for up to 4 VMs
  • You are allowed to reassign to another device after 90 days, or in the case of end-point failure
  • You are allowed unlimited backups of both running and stored VMs
  • The primary user of a Windows® VDA device has extended roaming rights, which means that he/she can access their VDI desktop from any device outside of the corporate environment, such as a home PC or an internet kiosk.


The Microsoft® VDI Suite

The VDI Suite is designed to provide the infrastructure, management and deployment components necessary for a Virtual Data Architecture.


There are two subscriptions available as device-based subscriptions:

  • The VDI Standard Suite includes the basic infrastructure and management components required for a VDI deployment.
    • Microsoft® Hyper-V™ Server 2008 R2
    • Systems Center® Virtual Machine Manager, System Center® Operations Manager (SCOM), and System Center® Configuration Manager (SCCM). The management functionality is limited to VDI only
    • The Microsoft® Desktop Optimization Pack. This allows you to implement technologies such as Application Virtualization
    • Windows® Server Remote Desktop Services allows you to deliver the VDI desktops.
  • The VDI Premium Suite includes all of the technologies of the Standard Suite as well as additional desktop and application deployment options:
    • Full Remote Desktop Services functionality which delivers sessions as well as VDI desktops
    • Microsoft® Application Virtualization for Remote Desktop Services

Frequently Asked Questions


1.   What is the difference between the Virtual Desktop Architecture license and the Remote Desktop Services (RDS) CAL

Remote Desktop Services allows you to run user applications on a single Windows® Server operating system with multiple sessions on one server, enabling each user to remotely access a full desktop or single application from the user’s local device via a remote protocol such as Microsoft® Remote Desktop Protocol (RDP).

An RDS CAL is required to log on to the RDS Server for accessing remote applications. The VDA license is required when accessing the full virtual environment.

2.   I’m buying VDI software from VMware®/Citrix®/other vendor. Do I still need Windows® VDA if I have VDI software from VMWare® or Ctrix®?

If you are accessing a Windows® client operating system (OS) as your guest OS in the datacenter from a thin client, Windows® VDA is the appropriate licensing vehicle. You need this regardless of the VDI software vendor you choose.


3.   What happens if I want a hoster to provide me with the Windows® desktop as a service?

Currently, there is no SPLA model for Windows® VDA. This means you will still require a Windows® VDA license.


4.   What is the main difference between the Microsoft® VDI Standard Suite and the VDI Premium Suite?

The VDI Premium Suite includes use rights for session virtualization (formerly known as Terminal Services), while the VDI Standard Suite is targeted at users accessing a virtual machine-based centralized desktop (VDI) and does not include use rights for session virtualization scenarios

May 2020