PowerShell 3.0 comes with two new help topics (among many others) that may be especially useful for those who work a lot with WMI (or would like to dive into it):
PS> help about_WMI -ShowWindow PS> help about_WQL -ShowWindow
"about_WMI" is a great introduction to WMI in general, and "about_WQL" has all the secrets you need to know to query WMI for information.
Should both files be missing, then you either do not run PowerShell 3.0, or you did not update the help files yet. Should only "about_WQL" be missing, then we recommend you update your help again. One of the benefits of PowerShell 3.0 updatable help is – that it is updatable! So every now and then, new help files like "about_WQL" are added.
This is how you update your PowerShell 3.0 help: Open PowerShell with full administrator privileges, then enter:
PS> Update-Help -Force