Pressing any 3 keys on my keyboard at once opens my default browser?

After experimenting a bit I found at that pressing any 3 keys opens my default browser, and I need help stopping this from happening. When I'm playing Minecraft I'm crouching, and use the two walk keys which is three keys, opens my browser thus making me fall. Can you tell me why this is happening and how to fix It? By the way, I'm using Windows 8.

Added (1). Also, pressing any 3 keys while in an interactive flash game doesn't do anything to my browser.

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