ARGGHH!!!! Why is my computer being such a ******?

AARR! my computer won't do any thing I want it to! It's like it just does whatever the frak it wants! If I try to check my e-mail it crashes (but on other computers it works fine!) and does all other kinds of funky stuff! Can ya' please tell me how to fix it before I put a musket ball through the screen!?