Why is Skyrim so laggy?

[mareksl]

Sorry for the late reply, I hope someone will read this
Actually the GPU temps are pretty stable. Normally (not running any games) the temp oscillates around 40-45°C, and while playing Skyrim, L.A. Noire or other games with high requirements, the temp rises to about 60°C.
And I don't really like the idea of a fresh winstall, as I have no backup drive, and don't want to reinstall all the programs and such (I'm a really lazy person). But I don't really think this is the issue, I have installed Win 7 pretty recently, a couple months ago I think.
Do you maybe have any other suggestions how to find out what is wrong, or to improve the situation / eliminate the problem?
Thanks in advance!

[Pip]

Well your GPU is not certified for Windows 7...which DirectX version are you using?

[mareksl]

DirectX 11

[TherealYeno]

Good thinking Pip. Your card does not support DX11.

[mareksl]

So I'll have to downgrade?

EDIT:
I see that you can't downgrade DX11 to 9 on Win7, but you can install them both seperately. The thing is I think that some games I installed already installed DX9 automatically, so it means it's already on here. Should I still try installing DX9?

[MetalSage]

I read on another site that turning off all AA setting in skyrim and turning them on directly through your GPU works.

[mareksl]

AntiAliasing you mean? I have it off.

[mareksl]

Sorry for bumping this, but I wanted to ask again if I should downgrade to DX9 somehow (or install seperately) and how to do it. Does anyone have an idea? Thanks!