Quote Originally Posted by Failia View Post
You'd get to play no problem. You just need to download it again. Your account information isn't stored locally. Unless I'm misunderstanding your situation. You pay to get the installation key. If you already have a registered account, it should work fine. If that would be the case, anyone that ever formatted their computer would be SoL.
You can't switch platforms for free. NintenPyjak64 is correct. If you have a PC account, you need to buy the PS3 version to play on PS3, and vice versa. Once you have a given platform tied to your account, you can download and play that account on that platform anytime, but switching/adding still requires a purchase.