The maximum number of simultaneous remote RDP sessions is two for all versions of Windows Server OS (+ one console session that can be accessed by connecting with the mstsc /admin command). These Remote Desktop sessions can be used for administrative purposes. They do not require the installation of an RDS Licensing Server or the purchase of RDS CALs.
A user can remotely connect to a Windows Server desktop if the user’s account is a member of the local Administrators or Remote Desktop Users group. Simultaneous RD connection is allowed only under different user accounts. If a shared administrative account is used to manage the server, when a second user connects via RDP under the same account, the first session is disconnected with this message:
Remote Desktop Connection
Your Remote Desktop Services session has ended
Another user connected to the remote computer, so you connection was lost. Try connecting again, or contact your network administrator or technical support group.
To find out which user disconnected your session, open the Event Viewer snap-in and go to the Windows Logs -> Security. Filter events by Event ID 4624. Information about where the last RDP login to this computer was made is included in the last event description.
On Windows, you can allow more than one RDP connection to run concurrently under a single user. For that, enable the Restrict Remote Desktop Services Users policy.
- Open the local Group Policy Editor console Win+R ->
gpedit.msc - Navigate to GPO Computer Configuration -> Policies -> Administrative Templates -> Windows Components -> Remote Desktop Services -> Remote Desktop Session Host -> Connections
- Set the Restrict Remote Desktop Services users to a single Remote Desktop Services policy value to Disabled
- Another GPO option that you can use to specify the maximum number of RDP connections to this host is the Limit number of connections. However, even if you increase the session limit here, the number of concurrent RDP connections is still limited to two until you install the RDSH role and add the RDS CALs.
You can also enable the “Restrict users of Remote Desktop Services to a single Remote Desktop Service” policy directly through the registry.
- Open the registry editor (
regedit.exe) - Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server
- Locate the REG_DWORD parameter called fSingleSessionPerUser and change its value from 1 to 0 (create this parameter manually if it is missing).
Or change the value of the fSingleSessionPerUser parameter from the elevated command prompt:
REG ADD “HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server” /v fSingleSessionPerUser /t REG_DWORD /d 0 /fWhen connecting under a shared account, each user joins their own RDP session. If you want to use more than 2 concurrent RDP connections, you must install the Remote Desktop Session role on the server and purchase RDS licenses for users and/or devices.