Option-1:
You can always upgrade your hardware.
My main computer just went through a major graphics upgrade.
Integrated graphics(awful, lagged tons on lowest settings), to HIS AMD Radeon HD 4670, and graphics are AWESOME!
Those cards aren't that expensive, so that would probably be a good option for you.
Option-2:
But if you don't do some hardware upgrade.......then were going to have to try a driver update, and maybe find a new driver.
Open your start menu, type in the search bar: "msconfig"...
It should open a "System Configuration" window, switch to the "Tools" tab.
Out of the list of tools, select system information. Click: "Launch", and wait...