What is it?
DRM Store Netscape Plugin - During the license acquisition process, content services can detect whether their end users have updated their computers by checking for component versions. Using the Windows Media Rights Manager SDK on the licensing server, the content service can retrieve version information from the client and then determine how to continue.
Description of npwmsdrm.dll from Microsoft
“When you integrate Digital Rights Management (DRM) into your applications, you can better protect and more securely deliver content cross-platform for a variety of scenarios, including streaming, progressive download, rentals, and subscriptions. You can create and distribute applications, content, services, and devices that incorporate Windows Media Digital Rights Management (DRM). ”