Need Help Understanding Graphics Card

I want to get my hands on a new directx11 graphics card. Now I'm currently running win7 ultimate on a directx 9 card :(

Blender doesn't work too well :( Not sure if its the graphics card or win7 but I'll use it as an excuse to get my hands on a new graphics card, lol

Now, My question is, The only Graphics cards that I can find that are DirectX11 are PCI Express 2.0 16X. But my Best expansion slot is a PCI Express 16X (Not 2.0).

Can I use a 2.0 card in a non 2.0 slot? If so What are the downsides of it? I really don't know this because I'm more of a software guy than a hardware one, lol.

You cannot, hardly anything is forward compatible, (except maybe USB 1.1). But there should be cards that fit PCI-E that have that capability.

Ok, honestly I didn't think so , but googled it anyway. And all the info I found just confused me horribly, so i decided to ask. thx :)