You just <i>can't</i> secure something like Windows, Linux, MacOS, because it's faulty by design. Any business that claims to be able to do so is selling snake oil.<p>Capability based operating systems <i>can</i> be made secure. Data diodes are a proven strategy to allow remote monitoring without the possibility of ingress of control. Between those two tools, you have a <i>chance</i> of useable and secure computing in the modern age, even against advanced threats.<p>Yeah... I feel like Cassandra, but here we are. You've been warned, yet again.