How to resolve a gwmi : Invalid class "WmiMonitorID" PowerShell error?

Question

I getting the following error:

gwmi : Invalid class "WmiMonitorID"
At line:1 char:1
+ gwmi WmiMonitorID -Namespace root\wmi | ForEach-Object {($_.UserFrie ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     + CategoryInfo          : InvalidType: (:) [Get-WmiObject], ManagementException
     + FullyQualifiedErrorId : GetWMIManagementException,Microsoft.PowerShell.Commands.GetWmiObjectCommand

while trying to grab my monitor's Serial ID using:

gwmi WmiMonitorID -Namespace root\wmi | ForEach-Object {
    ($_.UserFriendlyName -notmatch 0 | foreach {[char]$_}) -join "";
    ($_.SerialNumberID -notmatch 0 | foreach {[char]$_}) -join ""
}

I used this command about 2 months back and it worked flawlessly. (Was not even running PowerShell in admin)

Now with or without admin I get the error mentioned above. (also tried x64 and x86 both with/without admin)

Am I overlooking something?

May be your WMI is corrupt .Try these steps virtuallyboring.com/… — TheGameiswar
@TheGameiswar My WMI Control (Local) looks like the good one in the screenshot — newcool
The second screenshot looks as if there is an additional space in the class. You can see it in Invalid Class " WmiMonitorID" so it might be reading the whitespace. — Drew
@Drew Looks like you are right, but now there is a new error. i.imgur.com/jsRYonB.png — newcool
Now it looks like it is running each line independently instead of it being one larger expression. — Drew

newcool newcool · Accepted Answer · 2019-07-17T08:35:00

Thank you very much @Drew for pointing out the whitespace.

So it seems like whatever I was c&p the code from was adding extra spaces to the code which would make it end up looking like

gwmi(Space)(Space)WmiMonitorID(Space)(Space)-Namespace

or add extra spaces at the end

... -join ""}(Space)(Space)

The solution would be to copy it in a .txt or paste bin and make sure the extra spaces are not there before copying back to PowerShell.

How to resolve a gwmi : Invalid class "WmiMonitorID" PowerShell error?

1 Answers