Kills sessions hung on winlogon.exe; first attempt that uses the command line utilities; works pretty well.

Remove-BadWinlogonProcess.ps1

function Remove-BadWinlogonProcess {
    [cmdletbinding(SupportsShouldProcess)]
    param(
        [parameter(Mandatory, ValueFromPipelineByPropertyName)]
        [string]$ServerName
    )
    
    $DiscSessionWithNoName_RegEx = '^\s+(?<ID>\d+)\s+Disc'
    $Winlogon_RegEx              = '^ system\s+\d+\s+(?<PID>\d+)\s+winlogon'

    qwinsta /server:$ServerName | where-object { $_ -match $DiscSessionWithNoName_RegEx } |
        ForEach-Object { 
            $thisID = $Matches.ID 
            Write-Verbose -Message ('Checking session {0} on server {1}' -f $thisID, $ServerName)
            if ($thisID -gt 1) {
                qprocess /id:$thisID /server:$ServerName | 
                    findstr /i winlogon | 
                        Where-Object { $_ -match $Winlogon_RegEx } | 
                            foreach-object {
                                if ($PSCmdlet.ShouldProcess(('Killing off process ID ({0}) on server {1}' -f $Matches.PID, $ServerName), '', '')) {
                                    tskill $Matches.PID /server:$servername
                                }
                        }
            }
        }
}