Windows Server 2008R2 – How Often to Restart a Heavily-Utilized Remote Desktop Server (VM)

You're confusing remote desktop for administration with remote desktop services. Remote desktop for administration is for remotely managing a server via RDP. Remote Desktop Services is for remotely working from a server session as if the remote session were your workstation and running applications within that session via RDP. The conceptual aspects may be blurry but the licensing is certainly perfectly clear. In addition, remote desktop for administration is limited to 2 concurrent sessions and no additional licensing is required. Remote Desktop Services requires RDS CAL's and is limited to the number of RDS CAL's that you've purchased (this isn't a technical limitation, it's a licensing/legal limitation).

They may seem like the same thing and from a technical perspective they are (except for the concurrent session differences) but from a legal and licensing perspective they are two wholly independent things.

If you're running applications on the server while using remote desktop for administration you're most likely in violation of the EULA of both the server and the application.

You could just parse data from qwinsta. Qwinsta output normally looks something like this:

PS C:\> qwinsta
 SESSIONNAME       USERNAME                 ID  STATE   TYPE        DEVICE
 services                                    0  Disc
 console                                     1  Conn
>rdp-tcp#0         administrator             2  Active  rdpwd
 rdp-tcp                                 65536  Listen

The following queries for RDP connections by "SESSIONNAME":

$sessionInfo = qwinsta | foreach { (($_.trim() -replace "\s+",","))} | ConvertFrom-Csv
$rdpSessions = $sessionInfo | where {$_.SESSIONNAME -like ">rdp-tcp*"}
$rdpSessions

You'd get output similar to the below:

PS C:\> $rdpSessions


SESSIONNAME : >rdp-tcp#0
USERNAME    : administrator
ID          : 2
STATE       : Active
TYPE        : rdpwd
DEVICE      :