To enable true multi-user concurrent sessions, organizations are officially required to purchase Remote Desktop Services Client Access Licenses (RDS CALs) and configure an RDS Licensing Server. However, in testing, lab, or budget-constrained environments, tech-savvy administrators often look for ways to bypass this restriction. This is where modifying or patching the termsrv.dll file comes into play. What is termsrv.dll?
Monthly Windows Quality Updates or Cumulative Updates regularly replace system binaries to patch security vulnerabilities. When termsrv.dll is updated, your patched version is overwritten by a clean, restricted version from Microsoft.
Configure the and Remote Desktop Licensing roles. termsrv.dll patch windows server 2022
Every time Windows installs a cumulative quality update, it may replace termsrv.dll with an updated version. You will need to re-apply the patch or find the updated hex pattern matching the new build version after significant updates. The Official Alternative: Installing the RDS Role
Disclaimer: Patching system files violates the Microsoft Software License Terms. This guide is for educational and testing purposes in isolated lab environments only. Understanding termsrv.dll and RDP Limits What is termsrv
In Windows client editions (like Windows 10 or 11), this file restricts the system to a single concurrent session; if someone logs in remotely, the local user is locked out. In Windows Server 2022, it caps the connection limit to two administrative sessions. Patching this file involves altering specific hexadecimal values within the binary code to trick the service into ignoring these hardcoded limitations, thereby unlocking concurrent multi-user access without an RDS license server. Important Risks and Compliance Warnings
You need to search for the specific byte pattern that restricts concurrent sessions and replace it. While variations exist across update builds, the most common patterns for Windows Server 2022 include: For Standard Windows Server 2022 Build 20348+ 39 81 3C 06 00 00 0F 84 Replace with: B8 00 01 00 00 90 89 81 Alternative Pattern (if the above is not found): Search for: 8B 99 3C 06 00 00 8B B9 Replace with: B8 00 01 00 00 90 90 90 Configure the and Remote Desktop Licensing roles
Or simply reboot.
After saving the modified file: