WMI Filter to Identify an Exchange 2013 Server

I am in the process of creating GPOs to manage the process of applying appropriate WSUS Updates to machines in my organization.  The only machine giving me fits is I cannot seem to come up with a WMI query to Identify my Exchange 2013 Standard server so that I can make sure any update are applied to its operating system as well as to the exchange server itself.

Any suggestions?

Bob Hessenauer