I've been coding my website on Windows 7, just went on it on Windows 8, and it is messed up

Okay, so for the past year or so, I've been working on my website on Windows 7. But now, I just checked it on my new Windows 8 computer, and the margins are all off. Is there anything I can do to fix this? I've been working so hard on it, ditching my friends, playing 'hookie' to work on it, and now I just realized this, and its crushing me. Am I really screwed? I tried Google, found nothing. Hopefully one of you guys can help me out. Thanks.

I've been teaching myself HTML/CSS, I haven't taken any classes for it yet, so I'm sort of new.

Most of my CSS is in this fiddle: http://ift.tt/1G5PUF9