WMI EnableDHCP fails on disconnected adapter

It seems at least one other person is interested so here's what I found:

As far as I can tell it's a bug in WMI. To get around it, what seems to work is to directly set the appropriate registry values for the adapter. These are stored in the registry under

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\<guid>

The guid is contained in the IP_ADAPTER_INFO structure filled in by GetAdaptersInfo.

Set the EnableDHCP DWORD value to 1.

I also found it useful to clear the gateways using WMI SetGateways otherwise the old gateway(s) hang around.

I also found that when EnableStatic says it failed, it actually works.

This stuff is only relevant when the network is disconnected.

markh44's answer is still relevant 11 years later.

I found I had to add one additional step though: Set the DisableDhcpOnConnect value to 0. If I only EnableDHCP to 1, I found in the IPv4 Properties window that the IP address and subnet mask were gone, but "Use the following address" was still selected. Setting DisableDhcpOnConnect to 0 caused "Obtain an IP address automatically" to be selected.