How do I change my screen from widescreen to a square screen?

I just got a custom eMachines computer with Windows 7. It's a gaming computer, but when i run games, they're in widescreen, and they look horrible.

I was wondering how you change it to a square screen (full screen?).

I tried to do it by changing the resolution, but that stretched things even more.

Please help me. %26gt;_%26lt;How do I change my screen from widescreen to a square screen?
The problem is a custom emachines computer, you is not the issueHow do I change my screen from widescreen to a square screen?
It sounds like you have a bad monitor. What games are you playing?