This restriction is hardcoded into the Remote Desktop Services subsystem, specifically governed by the termsrv.dll (Terminal Services Library) file located in the C:\Windows\System32 directory.
This feature is strictly intended for server management, troubleshooting, and administrative maintenance.
For administrators managing multiple lab systems, a PowerShell script can automate the ownership changes and byte replacements. powershell termsrv.dll patch windows server 2016
net stop TermService /y net stop UmRdpService /y
Computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Connections officially configure session limits using Group Policy instead? This restriction is hardcoded into the Remote Desktop
For system administrators and power users, the built‑in limit on simultaneous Remote Desktop Protocol (RDP) connections can be a significant operational hurdle. While Windows Server 2016 is a robust platform for remote management, its default configuration—allowing only two concurrent administrative sessions—often falls short in team environments or automation scenarios. The solution lies in patching termsrv.dll , the core dynamic link library that governs Terminal Services. This article provides a comprehensive, step‑by‑step guide to patching termsrv.dll on Windows Server 2016 using both manual hex editing and automated tools, while also covering the technical details, security implications, and maintenance best practices.
Patching involves editing these hex values to bypass the license check, tricking the service into allowing unlimited concurrent connections. Step-by-Step Guide to Patching Termsrv.dll Step 1: Stop the Remote Desktop Service powershell net stop TermService /y net stop UmRdpService
Right-click termsrv.dll -> -> Security -> Advanced . Change the Owner to your administrator account.
Navigate to > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Connections .
Obtain a patched termsrv.dll designed specifically for your version of Windows Server 2016 (check build numbers via winver ). Copy the new file into C:\Windows\System32\ . Restart Remote Desktop Services powershell net start termservice Use code with caution. Important Security and Maintenance Notes
However, because this workaround directly violates Microsoft's licensing agreements and introduces administrative overhead during update cycles, production environments should always rely on legitimate Remote Desktop Services Client Access Licenses (RDS CALs).