Create new registry key NewNetworkWindowOff in:
HKLMSYSTEMCurrentControlSetControlNetworkNewNetworkWindowOff

Using task sequence this can also be used:

reg add "HKLMSOFTWAREPoliciesMicrosoftWindows NTCurrentVersionNetworkListSignaturesFirstNetwork" /v Category /t REG_DWORD /d 00000001 /f