Splunk is not supported on Windows 2000.
http://www.splunk.com/base/Documentation/latest/Installation/Systemrequirements
I know you're asking about Splunk specifically, but remember that that Microsoft does not support Windows 2000 servers anymore.
http://www.microsoft.com/windows/lifecycle/default.mspx
http://support.microsoft.com/lifecycle/?LN=en-us&x=10&y=10&p1=7274