Calling methods

When dealing with WMI, there are two kinds of methods that come into play, instance methods and class methods. Calling the WMI instance methods is similar to calling methods on any PowerShell object, that is, using dot-notation. For instance, WMI objects from the Win32_Service class have a StartService() method defined in them, which we can verify using Get-Member:

To call this method, we can store the instance in a variable and use the variable to call the method. Note that the method outputs a structured result type. The ReturnValue property of the output gives us the outcome of the operation. A value of zero means success. An example of a successful method invocation can be seen in the following screenshot:

Tip

You might notice that the preceding screenshot is an elevated session. If you try to start a service in a non-elevated session, you get a ReturnValue of 2, which means "warning".