What about a sandbox where all programs that came from the internet were locked in except for verified binaries. Then make it difficult to add new certificates,

What about a sandbox where all programs that came from the internet were locked in except for verified binaries. Then make it difficult to add new certificates, like require the user to enter a password (perhaps different from their login). Have microsoft say no program should require this, and as long they do a decent job of adding certificates themselves most users will not even bother learning how to.