HELP! Ok i have a Windows XP comp..and well my friend came on, and somehow got my screen to become widescreenish, idk how it happenend, he said the computer went blackscreen and he starting click random things, which trust me, pissed me off alot, i really need help, and fast, like before my parents get home so i don't get it from them, but i would really like help to change the comp screen back to normal.

PS: not sure if this is the correct place for this to post.