Thanks for the link to Windows Defender Offline. That is something to pass along.
What I've seen made, but only for a bit, was a small device that you plugged into a network port, and you plugged your laptop into it. It monitored bandwidth, showing you what hosts your machine was connecting to (even the rootkits and bad stuff), could throttle or block connections, and had a built in IDS/IDS (intrusion detection system/intrusion prevention system) that would lock out IP addresses or ports if it suspected they were malicious (SSL connections going to website addresses that are not HTTPS for example.) One could easily whitelist stuff, but it did a good job at stopping rootkits from phoning home.
