Enable Terminal Server and Terminal Server Application

Terminal Service access by default allows only two connections for remote administration. It was designed solely for remote administration and not for users to access.
If you need more than two users, such as to allow your users to connect remotely wtih their own desktop, do work, etc, then you must upgrade to what used to be called Terminal Server Application Mode or now called, Remote Desktop Services. However, this requires purchasing CALs (client access licenses) and , then once purchased, then you would:

1. Install the Remote Desktop Servicse Role.
2. Install the TS Licensing role service.
3. Open TS Licensing Manager and connect to the Terminal Services license server.
4. Activate the license server.
5. Install required TS CALs on the license server.
6. You then have to reinstall your apps in "Install Mode" so they will be available for your users.

Terminal Services Licensing (TS Licensing)
http://technet.microsoft.com/en-us/library/cc770371(WS.10).aspx

Windows SERVER 2008 r2 Remote Desktop Services:
http://www.microsoft.com/en-us/server-cloud/windows-server/remote-desktop-services.aspx

Remote Desktop Services in Windows Server 2008 R2: Step-by-Step Guides
http://blogs.technet.com/b/mattmcspirit/archive/2009/08/05/remote-desktop-services-in-windows-server-2008-r2-step-by-step-guides.aspx