Professional and Ultimate editions of Windows come with built in Remote Desktop (RDP) feature that lets you remotely access your machine from home or office. Unfortunately, this is limited to one concurrent user per session by default, which means that if someone connects to the computer remotely, whoever was logged in at this time is automatically logged off. even if the user is physically on the computer.
This is not a technical limitation but a licensing. For example, Remote Desktop in server versions of Windows by default supports two concurrent connections to remotely troubleshoot or administer a computer. More users can connect simultaneously, as long as the machine can handle it with the resources available and you have the required client access licenses for that particular server.
However, there are a few reasons why concurrent sessions would be useful for power users who may not necessarily be running servers. For example, if you have a dedicated media center PC running in the living room, you’ll be able to remotely access all of the files on the machine without interrupting the person watching TV.
Or if you’re sharing a computer with other users, concurrent Remote Desktop sessions will allow more than one person to access that system under a different or same user account, without shutting down each other. This is possible in all versions of Windows 7, Windows Vista, and Windows XP, by patching a file named termrv.dll located in %SystemRoot%System32.
Luckily for us, internet user deepxw has done all the dirty work a while back and posted his UniversalTermserve.dl patch for anyone to get their hands on. Simply download and unzip the file, then run the relevant file as administrator (right-click on the exe file and choose Run as administrator). Use UniversalTermsrvPatch-x86.exe for 32-bit systems and UniversalTermsrvPatch-x64.exe for 64-bit versions of Windows.
You should see a window like the one above where you can patch termsrv.dll to remove the concurrent remote desktop session limit and restore the original file at any time (a backup file is located at ‘windowssystem32termsrv.dll.backup’ ). After applying the patch, restart your system and you are ready to go.
To test this simply leave a session open on the PC where you applied the patch, then try and connect to the computer remotely from another machine. If all goes well both users will be logged on and activated.