I have a clean install of Windows Server 2012, and another server where I upgraded to 2012 from 2008.
I noticed that on the upgraded machine, when I type "Windows Update", an item for it appears in the start menu named "Windows Update", and when clicked a Metro-style full-screen UI appears for windows update.
Meanwhile, on the clean install of Windows Server 2012, there is no match for "Windows Update", although I can reach it indirectly by clicking the "View Update History", then clicking the breadcrumb in the address bar for Windows Update, all of which is a standard window that looks like it did in Windows 7.
So why are there two completely different looks for Windows Update on what is basically the same operating system? Could it have something to do with the fact that on the upgraded machine I had "Windows Desktop Experience" installed?