How can I enable multiple users login at a time in remote system?

Solution 1:

If you want more than 2 concurrent connections your computer is now considered a "Terminal Server" and you must pay for "Remote Desktop Services client access licenses" (RDS CALs) for people to connect. UPDATE: here is a link to a set of documents "License your RDS deployment with client access licenses (CALs)" that can walk you through the process of choosing a license and activating it on the server.

You can purchase CALs from the Microsoft store or other 3rd party resellers.

Solution 2:

Are you referring to Remote Desktop? If so, you can try this:

1. Log into the server and open MMC.exe.

2. File → Add/Remove Snap-in → Group Policy Object → Add → Finish → OK.

3. Double click Local Computer Policy → double click Computer Configuration → Administrative Templates → Windows Components → Remote Desktop Services → Remote Desktop Session Host → Connections.

4. Limit Number of Connections = 999999.

5. Restrict Remote Desktop Services users to a single Remote Desktop Services session = DISABLED.