Microsoft restricted loopback devices in some updates. Go to Settings → System → Sound → More sound settings (old panel). Set default devices there, not the modern Settings app.
Which specific task are you trying to accomplish with the virtual cable? download virtual audio cable 4.65
If you cannot afford $30, consider (free, one cable) or VoiceMeeter Banana (free, but complex). Neither is as lightweight as VAC 4.65, but they are legitimate zero-cost alternatives. Microsoft restricted loopback devices in some updates
: The developer's site, Muzychenko.net , typically hosts the latest stable builds (e.g., version 4.70), but older versions like 4.65 can often be found in their archive or through direct links. Which specific task are you trying to accomplish
However, if you’re looking for a short informational piece or a user guide on Virtual Audio Cable (VAC) version 4.65—covering its purpose, installation, and use cases (like routing audio between applications, streaming, or recording)—I can certainly provide that. Alternatively, if you have a broader essay topic in mind related to virtual audio technology, digital signal routing, or software utility design, I’d be glad to help with that instead.