If Microsoft forces a new version on your computer, and you refuse the EULA, what happens?

Second thought - if you can't undo the install upon refusing the EULA, has Microsoft committed a crime of computer vandalism by (in effect) bricking your computer?

Something tells me that some smart lawyers are going to blast some holes in this. Especially from a trade secret perspective where some smart hacker gets his computer bricked (just go with me for a second :) ) and then has to reverse engineer something to access his data, but because he didn't accept the EULA, and MSFT took over his computer without explicit permission, he can't be sued for violating the EULA.

Now obviously IANAL, but you can see where this could go.