file is the core library for Microsoft’s Remote Desktop Services (RDS). By default, consumer versions of Windows (like Windows 10/11) limit users to one active RDP session, and Windows Server editions typically limit concurrent connections to two unless Remote Desktop Session Host (RDSH) is fully configured.

Attempt to log in with a third user account. If successful, your patch is working!

Before Server 2019, patching termsrv.dll was straightforward:

To allow multiple sessions, you need to find a specific byte string and replace it. While there are "one-click" patches available online, doing it manually via a Hex Editor (like HxD) is the safest way to ensure no malware is introduced. Open termsrv.dll in your Hex Editor.

Downloading pre-patched DLLs from "exclusive" or "free" websites often bundles malware or backdoors into your system.

Many so-called Server 2022 patches are simply hex edits meant for Windows 10 or Server 2019. Applying them to Server 2022 often causes: