Hi David Waston,
I looked on microsoft website and I found Information about Service Pack 2 for Windows Vista and for Windows Server 2008
"Windows Vista Service Pack 1 (SP1) is a prerequisite for installing SP2 in Windows Vista. If you use Windows Update or the Automatic Update feature in Windows Vista, you will not be offered the option to install SP2 until you first install SP1.....
Windows Server 2008 does not have a similar requirement. Windows Server 2008 SP2 is the first service pack available for this product."
And if you open the definition in Patch and Management > Right-CLick > Properties > Double-click one of the kb....exe > Go on tab "Affected Product" > It makes sense.
I hope it will help you to clarify that up unless I missed something,
Good luck!