If you change the vendor name to Microsoft in the "Patch Management" screenshot you shared you would then be able to set up Windows updates checks. The condition you shared in the screenshot is more related to BigFix client itself, not to Windows updates. The Check type is the definition of what check you want to do for that condition, for instance if you do "Installation" the check will look at if the client is installed, "Enabled" would check if the software you are checking is not disabled on the client, and "Up to Date" will look at the latest version of the client based on the gathered details by ISE of that software. I think the check types might change based on the condition you create.
Regarding the "Check Patches Installed", that is the severity level you want to check for those patches. By selecting "Improtant & Critical" you are saying I only care about looking if the important and critical patches are installed which is the common way to do it.
