Microsoft would do nothing much - because if it worked they wouldn't know and if it doesn't they wouldn't care. Problem is it will wait for you to register it for a month and; however much Iamroot says it won't it will switch itself off and not work. Won't ruin the computer but you'll have lost a months worth of programs and saves - not files though.
A Knight is sworn to Honour. His heart knows only Virtue. His blade defends the helpless. His might upholds the Weak. His word speaks only truth. His wrath undoes the Wicked.