Minecraft freezes after Mojang logo comes up and closes when task manager is opened

Summary: My little brother updated our Minecraft to 1.4.2 and went into Creative mode to see the new features. We always use Optifine on our Minecraft to avoid lag so when he noticed that the sky, fog, etc were visible (due to us not having the latest version of Optifine) he clicked options which caused Minecraft to freeze. He closed the window and restarted Minecraft, but after the Mojang logo was shown Minecraft froze with a black screen. When Task Manager was opened Minecraft immediately closed. It continues to do this any time we start up Minecraft.

What I expected to happen: Minecraft booting up after I log in, like it usually does.

What did happen: Minecraft froze after the Mojang logo disappeared. Note: according to the task bar on the bottom of the screen along with Minecraft being open was an unknown "Minecraft Minecraft..."

Steps to reproduce
1. Have Optifine 1.3.2 active
2. Go into a Creative world
3. click Options