Hi, and welcome to KORG!

Here's your code:
 Code:
$pathOfWFBSHInstaller="msiexec /qn /i \\SERVER\netlogon\Kix32\Apps\TrendMicro\Agent_Installer.msi"
$strComputer = "." 
$strOutput = ""
$serviceCount = 0
$totalServiceCountToCheck = 3

; check if WFBS-SVR is installed by detecting service ntrtscan, tmlisten, svcGenericHost are exist or not
$objWMIService = GetObject("winmgmts:{impersonationLevel=impersonate}!\\" + $strComputer + "\root\cimv2")
$colItems = $objWMIService.ExecQuery("Select * from Win32_Service")
For Each $objService in $colItems
  $strOutput = $strOutput + $objService.name + @CRLF
  Select
    Case $objService.name = "ntrtscan"
      $serviceCount = $serviceCount + 1
      ;? "Service " + $objService.Caption + " is " + $objService.Started
    Case $objService.name = "tmlisten"
      $serviceCount = $serviceCount + 1
      ;? "Service " + $objService.Caption + " is " + $objService.Started
    Case $objService.name = "svcGenericHost"
      $serviceCount = $serviceCount + 1
      ;? "Service " + $objService.Caption + " is " + $objService.Started
  EndSelect
Next

If $serviceCount <> $totalServiceCountToCheck
  Dim $WshShell
  $WshShell = CreateObject("WScript.Shell")
  $WshShell.Run($pathOfWFBSHInstaller)
EndIf