Problems setting up Active Directory

I’ve installed Windows 2000 Server onto my PC as a test PC (Standalone) When I set it up, I set it up as a workgroup PC. I want to install Active Directory and install it as a PDC so that I can learn Windows 200 properly. When I run the DCPROMO utility, I enter all the credentials required. When it comes to installing the active directory it gives me an error message saying “Active Directory Installation Failed. The operation failed with the error: The network location cannot be reached”. What is it trying to reach?? And how do I get AD installed from a workgroup computer then??