Some things are perfect candidates for script automation, but this may not be one of them. I'm not saying that its impossible to handle through scripts, but may not be the best practice.

If you are dealing with many different NIC manufacturers and/or models then there isn't going to be any one place in the registry to make these changes. Also, it may depend on how many other network "adapters" (i.e. virtual adapters, dial-up adapters, or just plain network adapters) are installed on any given system.

Your best bet is to find out what changes are made in the registry as you make setting changes to the NIC. I use a utility called InstallWatch Pro to take a snapshot of the system before and after installations/setting changes/etc. and view the changes. It can be found at: http://www.epsilonsquared.com. I'd suggest using this tool to "capture" the setting changes on each different type of NIC in your environment.