how did this guy get to be a star?

Because his part as Dwight was freaking awesome, that's how. Plus the couple of movies I've seen with him in them were pretty good. He did one recently where he was a wanna be Superhero that I thought was basically Dwight, and then House of a Thousand Corpses I thought he was pretty good in too.

By the way, I am right behind you.

Dwight Schrute and The Office.

He ain't that much of a star if the only work he gets these days is doing movie trailer voice over work.

He does voiceovers for movie trailers? Cool. Could you please leave a link or two please?

"he's so goofy and a nerd." you just answered your own question as to why he's on the big screen. people luv those lovable nerd types.

Well, you should know, seeing as you're obviously a goofy little troll living in his mothers basement, and seeing as how your whole existence revolves around masturbation and anime, I don't think you're really in any position to be criticizing anyone for being a "nerd." At least Rainn Wilson is getting laid -- the closest you're ever going to get to a warm body is the pizza delivery guy.