Thanks to Daniel Petri
As you probably all know by now, Windows XP Professional allows you to only use one concurrent Remote Desktop session. The moment the remote user connects to the workstation by using Remote Desktop, the locally logged-on user is locked out of the computer, and the remote user, if he or she are using the same credentials as the user which is currently logged-on, see the same desktop as the current user saw right before he or she were locked out. If the remote user is using different credentials than the user which is currently logged-on, then they must be members of the administrators local group in order to log-off the current user, and create a new user session.
All this is well and fine, but the problem is that sometimes one might want to have more than one concurrent Remote Desktop session.
Luckily for us, ever since the first days of Windows XP, there were people who managed to get around this limitation by editing a file on the XP machine, and making some registry changes. When Windows XP SP2 came out, the patched file got overwritten by the new version of the file, and so was the case in Windows XP SP3.
Now, there’s a new version of the patched file available for you to use. Actually, this is not really a news item, it’s just something I came across and decided to write about because I recently got some questions about this issue from a couple of readers.
However, be warned. Before you begin, I need to warn you that patching the file and allowing more than one concurrent Remote Desktop session will violate a few lines in the Windows XP EULA. Proceed with caution and at your own risk. I shall not be liable for any damage caused to you, your computer, your data or your dog/cat because of this.
First, download the patched file, registry file and instructions.
The patched file is termsrv.dll version 5.1.2600.5512 which was updated when installing Windows XP Sp3.
Next, read and follow the simple the instructions.
Installation instructions (provided in the readme file):
1. Go start–> run (paste C:\Windows\system32\dllcache) and rename the termsrv.dll to termsrv.dll.bak.
2. Go to \Windows\System32 folder and rename termsrv.dll to termsrv.dll.bak.
3. Copy the new SP3 patched termsrv.dll to \Windows\System32 folder.
4. Run the included registry patch “ts_concurrent_session_patch.reg” (by double clicking it), it will update the relevant registry values which are relevant to the concurrent sessions support.
5. Restart windows.
6. Now try to connect with more than one Remote Desktop session.
Note: if you are currently using Terminal Services, you would have to start windows in safe mode before you can overwrite the termsrv.dll file.
Domain Users Note: If registry values are automatically removed very time you reboot the computer (domain environments), create a .bat file with below scripts and run it in the startup(copy to C:\Documents and Settings\\Start Menu\Programs\Startup).
@ECHO OFF :: :: @REG ADD “HKLM\SYSTEM\ControlSet001\Control\Terminal Server\Licensing Core” /v EnableConcurrentSessions /d 1 /t REG_DWORD /f >nul @REG ADD “HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon” /v EnableConcurrentSessions /d 1 /t REG_DWORD /f > nul @REG ADD “HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon” /v AllowMultipleTSSessions /d 1 /t REG_DWORD /f > nul :: ::