In Windows 8 and 8.1, like in previous Microsoft client OS versions, only one simultaneous incoming RDP connection is supported. It means that only one user (one session) can simultaneously connect to a Windows 8 computer using the Remote Desktop. In most cases it is enough, but sometimes it would be useful if multiple users could work simultaneously in their own sessions. A good example can be a computer used as a Media Center, when video is played in the console session and you have to use a system without stopping video on TV.
When you trying to start the second RDP session to a computer with Windows 8, a message appears that another user is already signed in and his session can be closed.
For example, in the server version of Windows supports two concurrent administrative connections to the individual sessions (in case of the terminal RDS server this number may be even higher).
Nevertheless, you can find a special patch in the web that allows to ignore this restriction. Due to this patch, multiple users can simultaneously connect to Windows 8 / Windows 8.1 computer over RDP.
So, the patch replaces the original system file %SystemRoot%\System32\termsrv.dll (a library used by Remote Desktop Services).
Here are the links to the modified library versions:
Before you replace the library, back up original termsrv.dll using the command:
copy c:\Windows\System32\termsrv.dll termsrv.dll_old
Now, if something goes wrong, you can always roll back to the original configuration, replacing the current file with the original termsrv.dll_old.
Download the archive with the library for your Windows version.
In Windows 8 you firstly have to change the values of the following keys in HKLM\System\CurrentControlSet\Control\Terminal Server\:
- fDenyTSConnections (DWORD) -0 (the key allows to remotely enable RDP on your computer)
- fSingleSessionPerUser (DWORD) — 0
This can also be done in the command prompt:
REG ADD "HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server" /v fDenyTSConnections /t REG_DWORD /d 0 /f
REG ADD "HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server" /v fSingleSessionPerUser /t REG_DWORD /d 0 /f
Then go to C:\Windows\System32, find the file termsrv.dll and open its properties.
By default, the owner of this file is TrustedInstaller and even the administrator doesn’t have any right to replace it.
Go to the Security tab and click Edit button. In the access list, find the local administrators group and give it full control over this file and save the changes.
The next step before replacing the library file is to open the service management console (services.msc) and stop Remote Desktop Services.
Copy termsrv.dll from the downloaded archive for your Windows version to %SystemRoot%\System32\ (with replacement).
After you replaced the file, run Remote Desktop Services and try to create two RDP sessions on the patched computer from different accounts. If you did everything right, two separate Remote Desktop session would open.