Eventualmente, consegui resolver o problema usando esse utilitário, que adicionou novamente as chaves Winsock ausentes: link
A Winsock reset utility with a few unique features. In addition to the usual fixes, it can scan for missing DLL files or reg entries and report; also allows you to import either the DEFAULT Winsock registry keys for that OS, or you may choose to import backups of your own Winsock registry keys from other Control Sets in the Registry (e.g. HKLM\System\ControlSet00x\Services\Winsock2, etc.) Fully portable