How to turn off windows xp compatibility mode?

Call me stupid if you have to, but I've never had this problem before I tried to download both battlefield 3, and Titanfall. Not at the same time of course... but I run windows 8 on my computer, and it keeps saying download failed, you must have windows vista 6.0 or higher. I read some of the solutions and people are saying to turn off compatability mode, except I can't figure it out. I know this probably makes me seem idiotic, but I've played the sims since January, and it worked just fine. Can anyone help me figure this out?