Terminal Server has exceeded max number of connections

I received a call requesting assistance one of our users is unable to remote into an SQL server. He is receiving the following error:



I tried to remote as well but received the same error. Then I started researching on how to find the users that are logged in, so that he may communicate with them and ask them to log off, but this brought a very limited amount of information. I found out that the class Win32_LoggedOnUsers doesn't really give you that information, but then I found out that there is a way to bypass the maximum number of connections by using the following command:

%systemroot%\system32\mstsc.exe /admin

Once I logged in I was able to go through the Task Manager and find and log off the extra user, but I was not happy with this solution. I feel like it might not always work. After further looking into this issue I found in Learn-PowerShell that I was able to use the WMI Class Win32_Process to get the Explorer.exe process and get the Owner, thus revealing the logged on users. 

Script found in sauce:

Function Get-WMIComputerSessions {

<#

.SYNOPSIS

    Retrieves tall user sessions from local or remote server/s

.DESCRIPTION

    Retrieves tall user sessions from local or remote server/s

.PARAMETER computer

    Name of computer/s to run session query against.

.NOTES

    Name: Get-WmiComputerSessions

    Author: Boe Prox

    DateCreated: 01Nov2010

.LINK

https://boeprox.wordpress.org

.EXAMPLE

Get-WmiComputerSessions -computer "server1"

Description

-----------

This command will query all current user sessions on 'server1'.

#>

[cmdletbinding(

    DefaultParameterSetName = 'session',

    ConfirmImpact = 'low'

)]

    Param(

        [Parameter(

            Mandatory = $True,

            Position = 0,

            ValueFromPipeline = $True)]

            [string[]]$computer

    )

Begin {

    #Create empty report

    $report = @()

    }

Process {

    #Iterate through collection of computers

    ForEach ($c in $computer) {

        #Get explorer.exe processes

        $proc = gwmi win32_process -computer $c -Filter "Name = 'explorer.exe'"

        #Go through collection of processes

        ForEach ($p in $proc) {

            $temp = "" | Select Computer, Domain, User

            $temp.computer = $c

            $temp.user = ($p.GetOwner()).User

            $temp.domain = ($p.GetOwner()).Domain

            $report += $temp

          }

        }

    }

End {

    $report

    }

}

But I didn't quite need all this so I simply made a one line :




(gwmi win32_process -computer SERVERNAME -Filter "Name = 'explorer.exe'").GetOwner().User 

Now I am able to find out the users that are logged in without having to remote into the server. 

Hope this might help other people out there!