If the Demo runs ok, will the full game?

[Lemur]

Not only will the game run fine on the system you describe, it will probably run better than the auto-configuration system will acknowledge.

Check out this thread:
https://forums.totalwar.org/vb/showt...ight=1600+1200
to optimize your preferences. There's a quick hack that will let you run at 1600 x 1200, and a more involved hack that will give you all graphics options. Either will do the trick.