The termsrv.dll file is a part of the Windows Terminal Services (also known as Remote Desktop Services) and is responsible for managing remote desktop connections.

Open an elevated Command Prompt:

Patching termsrv.dll on Windows Server 2012 R2 is typically used to enable concurrent RDP sessions without requiring a full Remote Desktop Services (RDS) deployment and its associated licenses.

There are two primary ways users bypass the default RDP session limit: