I had widows7 with directX 11(graphics card not support direct x 11).But i want to play Assassin's Creed 1 which only requires directx9or10.Can i run both directx together? If yes ,how to do it?
CPU : Pentium (R) Dual Core CPU E5500@2.8GHz
Graphics Card(integreted) : Intel R gma 3100
Well, TBH it doesn't make much difference if you used DX9/11 or both (even if it was possible). The issue you have is the iGPU, which is the Intel GMA 3100. This GPU is simply not good enough to play that game, and perhaps even at lowest settings. It would be like a slide show. The iGPU is just not designed for gaming.
DirectX is a language for telling graphics cards what to draw on the screen.
Just because your card speaks the language, doesn't mean it's powerful enough to do it quickly.
If a card can't do it fast enough, then it won't trick your eye into thinking the image is moving.
I'm afraid that your PC is only fast enough to run very basic games.
I'd suggest taking up a hobby with classic games & save up for something a bit better.
or better still, get a console