I would like to take this opportunity to share some guidelines on acquiring Windows Desktop Licenses which will help protect you and your organization from piracy/usage of unlicensed software, and the associated risks.

Windows Desktop Licensing

1. Licensing the Windows Desktop Operating System on new PCs: There are only two ways to acquire the original Microsoft license on your new PC.

An OEM key – It is a license type that is provided by your PC manufacturer or one assembled by your system builder where the Microsoft Windows Operating System is pre-installed and supported by that PC manufacturer or the system builder partner.
A Retail key – This version is known as the Microsoft Fully Packaged Product (FPP) version and is suitable if you are about to procure licenses for 5 or less PCs. Go here to know more about the types of Consumer or Retail Keys.

Pre-installed OEM software is the least expensive and most efficient way to acquire a genuine Microsoft software license on your new PC.

2. Licensing the Windows Desktop Operating System for existing PCs: To convert the install base of Non-Genuine Windows Client OS, Microsoft offers a variety of Windows Legalization Solutions to address all customer types. All legalization solutions can only be used for existing PCs with unlicensed software.

Microsoft has introduced Get Genuine Solution (GGS), Get Genuine Kit (GGK) and Get Genuine Windows Agreement (GGWA) legalization offerings to help legalize Windows on existing PCs only. GGS/GGWA offers a full license of Windows 7 Professional and is recommended for customers who need 5 or more licenses. GGK is offered to customers who generally need smaller quantities.

With the exception of FPP, all Windows Desktop licenses including OEM and legalization solutions (GGS, GGK or GGWA) is ‘tied’ to the device to which it is first assigned and may not be reassigned to any other PC. Further, all these licenses are “perpetual” only as long as they are used on the same PC.

3. Acquiring Windows Upgrade license through Volume Licensing for new or existing PCs: With the exception of legalization solutions like GGS/GGWA, Microsoft Volume Licensing programs cover Windows Upgrade license only and do not provide a full Windows desktop license. Customers must acquire a full qualifying version of the OS through preinstalled OEM/FPP or legalization solutions first to be eligible for a Windows Volume License Upgrade (Microsoft Open License Program, Enterprise Agreements and Select Agreement).

Hope this helps.