Remote access for Windows Server 2012

Question

Hello there, 
I have a dedicated Windows Server 2012 server, and I need remote access from a PC from a Mac OS X simultaneously. 
Today, I use Remote Desktop Connection on the Mac and TeamViewer on your PC. 
The problem is that the PC loses connection when Remote Desktop Connection is closed! 
What is the solution for either the PC or the Mac or the two at the same time to access the server desktop? 
Is there a setting that allows TeamViewer this? 
Should I use or purchase additional software? if so, which one? 
In short, what is the best solution to this problem? 
Thank you!

Answer 1

We use RDP through VPN, so there is no forwarding ports, it is as if we are on the same network. This way, you do not have to worry about hackers, as you are in a secure VPN.  
Are you doing this from a different office, from home, from a computer in the next room on the same network?  What level of remote access are you looking at?
RealVNC is a good solution, but again, if you are outside the network, you will either need to go through a VPN to keep it secure, or open ports on the firewall.   RDP will give you the ability to have two concurrent users (although with different usernames)
logged on at once.  The limitation of only one user is a session limit on the computer itself,  if one person is logged in as administrator, if someone else tries to RDP and log in as administrator, they will take over the session.  This is
the same with other solutions. RealVNC is using a console session,  so if another person uses VNC, they will see the already open console session,  and possibly take over the others VNC session.