i can run the demo (not beta) fast as long as i keep shader quality low and texture not on ultra cuz then it crashes can you guess my system?

im getting a new comp: 2.4 pentium core im think and an 8800 single sli card is it any good?

Company of heroes 2 comes out this year and i just cant wait!

When i download the demo, it works really slow why does it work like that?