korell: What graphics card do you have? I know you said you think it is an nvidia, but can you confirm, and how old is it? OpenGL is part of the nvidia drivers, I'd find it hard to believe you don't have the OpenGL libraries on your machine.
Johnmourby: It shouldn't be that old. I had my PC built in march of last year (You may have guessed I'm not very tech savvy). Is there any way I can find out what kind of card I have exactly without opening my PC up?
In Windows 7 go to Control Panel, click on Hardware and Sound, and then you should see a link to the Device Manager program. When you're in the Device Manager, look under Display Adapters and that will tell you what kind of card you have :)
