Is there a version for Windows Core or instructions to install on Windows Core (No GUI)?
If msiexec works at the command line, you should be fine. Docs have info on how to do silent install
http://www.splunk.com/base/Documentation/4.1.3/Installation/InstallonWindowsviathecommandline
Enable SplunkForwarder, disable indexing of the Windows System event log, and run the installer in silent mode
msiexec.exe /i Splunk.msi SPLUNK_APP="SplunkForwarder" FORWARD_SERVER="" WINEVENTLOGSYSCHECK=0 /quiet
Link to docs:
If msiexec works at the command line, you should be fine. Docs have info on how to do silent install
http://www.splunk.com/base/Documentation/4.1.3/Installation/InstallonWindowsviathecommandline
Enable SplunkForwarder, disable indexing of the Windows System event log, and run the installer in silent mode
msiexec.exe /i Splunk.msi SPLUNK_APP="SplunkForwarder" FORWARD_SERVER="" WINEVENTLOGSYSCHECK=0 /quiet
I don't know of any off the top of my head...
Only thing i can think of is install on a regular windows 2008 r2 box, then copy the program files over to the core box. You would then need to monkey in the registry of the core box to get the splunk services set up.
Not something for the faint of heart I'm afraid. Although, since they support linux, it would make sense for them to make a version that can be installed through command prompt only means.
If copying the files from one box to another, the command 'splunk enable boot-start' will try to create the services entries to manage the splunk instance.
Sorry to reply to my own comment, but check out:
http://www.splunk.com/wiki/Deploy:SplunkForwarder_for_Windows_installscript
It's a script that automates the install of splunk as a forwarder. You may be able to use this as a starting point.