Answer:
I make billions of dollars selling Windows. Who am I?
A canvas full of stars.
When it's dirty this should never be aired in public.
A squiggly line tells you when you've done it wrong
I occur twice in eternity. And I'm always within sight.
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?