If I were you, I would first test that PC with a Linux version. That does not cost you anything and after a bit of getting used to Linux, you may even want to keep it. It can do everything you want to do.
There are many Linux choices. But the most used one is Ubuntu ( http://www.ubuntu.com/download/ubuntu/download
But here is a list of select, recommended distros which you might want to study: ( http://www.linux.com/learn/docs/ldp/282996-choosing-the-best-linux-distributions-for-you