With the Enterprise Source Licensing Program you gain access to Microsoft Windows source code for internal development and support. Your IT staff can use the source code to improve the performance of Windows systems and related applications, enhance supportability and help enhance system security.
Check Your Benefits
With the Enterprise Source Licensing Program (ESLP) benefit, Microsoft Software Assurance customers with 1,500 or more licensed desktop PCs in the systems pool can access Microsoft Windows client and server source code for internal development and support purposes.
To determine the geographic markets in which source code can be made available under Enterprise Source Licensing Program, please consult the Shared Source Licensing Programs: Program Availability.
Get more information though VLSC
To acquire source code, your Software Assurance Manager starts by signing into the Microsoft Volume Licensing Service Center (VLSC) tool to get more details on using this benefit.