OS X :: Accidentally Scanned From Bootcamp And Reset - How To Start Reinstall Process

I have, somehow, reset my entire OSX. The Dock is now huge, all of my icons are now reset to the default ones when I originally bought the Macbook Pro. The software is still there but the icons have been reset. The icon no longer bounces when I open it.

And I know exactly why. I was in Windows through bootcamp doing routine maintenance and decided to do a full scan using Microsoft Security Essentials. I forgot to have it ignore the E:/ drive which is where MacOSX installed. It must have got 25% through scanning it before I realized it. I don't even know if that can cause a problem but it obviously did. I booted into OSX just to double check everything was ok. It loaded fine, all icons where there and seemed like everything was ok. Except the icons weren't bouncing when I opened up an application even though it was checked in the preferences. This frustrated me so I rebooted again to see if that would fix the issue and now here I am. Completely back to factory defaults. My software is still there but the Dock reset itself and it seems as if other things reset. I'm doomed. So how do I start a reinstall process? Insert the Snow Leapord disk?