Test WMI connection

Question

Hello. I've been reading quite a bit about testing WMI connections towards remote computers, but I haven't quite found the answer I am looking for.
What I am going to do is several gwmi calls against all the computers in the domain. This will surely lead to several "The RPC server is unavailable" error messages as all computers will not be powered on and some "No Access" messages.
Since my script includes several gwmi calls for each computer I want to test the gwmi connectivity against each computer before I run all the gwmi calls. I want this test do be done as quickly as possible.
Some pages I've visited suggests using "Test-Connection", but that doesn't test towards for example "No Acces" does it?
I've found this (see code below) and I'm wondering if that is the best way to do it:
$wmi = gwmi win32_bios -ComputerName $pc-ErrorAction SilentlyContinue
if ($wmi)
    #put all wmi calls here.
Kind regards,
Nils Rune

Answer 1

Hi, I try to use your script
$ping = New-Object System.Net.NetworkInformation.Ping
$Reply = $ping.send($strComputer)
if ($Reply.status –eq “Success”) 
{ $WS.Cells.Item($row, 2) = "Online"
 try {
 $results = Test-Connection $strComputer
 If ($results) {
 $ws.rows.Item($row).Font.ColorIndex = "5"
 $WS.Cells.Item($row,3) = "WMI OK" } 
 Else {
 $ws.rows.Item($row).Font.ColorIndex = "3"
   $WS.Cells.Item($row,3) = "WMI Failed" }
 catch
    Write-Host "Test-Connection Failed"
 Else { 
 $WS.Cells.Item($row, 2) = "Does Not Ping"
 $ws.rows.Item($row).Font.ColorIndex = "3"
BUT at the first line, I added this parameter to specify that the script has to read the computer'name
from a TXT file :
$strComputer = Get-Content "C:\Temp\ComputersList.txt"
When I run the script, I got the error : "You cannot call a method on a null-valued expression" Do you
have an idea please ?
Thank you