Microsoft restricts simultaneous connections based on your operating system edition and the presence of Remote Desktop Services Client Access Licenses (RDS CALs).
icacls C:\Windows\System32\termsrv.dll /grant administrators:F Use code with caution. Step 2: Stop the Remote Desktop Service universal termsrv.dll patch windows server 2012 r2
The Universal Termsrv.dll Patch modifies the binary code inside the termsrv.dll file to remove the hardcoded check for the session count, effectively enabling multiple users to log in simultaneously without installing the official RDS role. Risks and Compliance Issues Risks and Compliance Issues Back up your server
Back up your server or take a virtual machine snapshot. If the file becomes corrupted, the RDP service will crash entirely. By changing a few bytes of data, the
The "Universal Patch" is a method of modifying the hexadecimal code inside this specific DLL file. By changing a few bytes of data, the operating system is tricked into ignoring the built-in connection limits, effectively allowing unlimited concurrent RDP sessions. Prerequisites Before Patching
Windows protects system binaries via TrustedInstaller . You must change file permissions to modify it. Open Command Prompt as Administrator. Grant ownership to the Administrators group: takeown /f C:\Windows\System32\termsrv.dll /a Use code with caution. Grant full control permissions:
Replacing or patching system binaries can introduce malware if sourced incorrectly. Step-by-Step Implementation Guide