Charlie Russel's Blog

I have a bunch of scripts I use when I’m building a lab to install “stuff” (that’s the Technical Term we IT Professionals use) that I need to manage and work with a virtual machine. Now, when I build from a SysPrep’d image, that’s not an issue, but if I have to build from an ISO, I want to automate the process as much as possible. So I have a couple of Setup scripts I run that install gVim, HyperSnap (my screen capture tool), and various other things.

As I was building a new lab this week, I realized that those scripts were all designed to deal with full GUI installations, and had no provisions for not installing applications that make no sense and can’t work when there’s only a Server Core installation. So, time to find out how I can tell if I’m running as Server Core, obviously. A bit of poking around, and I came up with the following:

$regKey = "hklm:/software/microsoft/windows nt/currentversion"
$Core = (Get-ItemProperty $regKey).InstallationType -eq "Server Core"

(You could do that as a single line, obviously, but I broke it up to make it easier to see on the page. )

The result is stored as a Boolean value in $Core, and I can now branch my installation decisions based on the value of $Core. (Note there ARE other ways to determine whether you’re running on Server Core, but they appear to all be programmatic ones not well suited to the avowedly non-programmer IT system administrator types like me. )