Are you running Server Core installations of Windows Server 2008, 2008R2, 2012, or 2012R2? If you can, you should be. And if you are, or just like using PowerShell for everything, you should really take a look at the Windows Update PowerShell module available from the TechNet Script Center, by MVP Michal Gajda. It’s gotten quite good over the last few revisions, and I find myself loathing working on systems where it’s not been installed.
If you want an easy way to go about updating your Windows installations from PowerShell (locally or remotely), consider giving this add-on a try. I think you’ll like it.