Instructions
Load the game. The menu screen will appear in front of you. Click on the button that says "Options" and then click on "Video Settings." There is a box labeled "graphical quality." Your current general settings will be shown there as "best," "medium" or "low." Reduce it to "low" for the biggest improvement.
Adjust the advanced graphics. The graphical qualities tool adjusts everything in general, but if you want to pick and choose which graphics to change, use the advanced graphics section. Under "graphical quality," you will see a small check box designed like a "+" sign with the caption "show advanced options" next to it. Click on that to be taken to the advanced video options.
Lower the screen resolution. Lowering the resolution will put less of a strain on your computer's hardware when running the game. You will see numbers in the boxes under "Battle Map Resolution" and "Campaign Resolution" that may say 1280 x 768 or some variation. This is your resolution. Click on the small triangle next to the numbers. A drop down menu will appear with more resolution options. Choose one with smaller values, such as 1024 x 768, and see if that helps.
Reduce anti-aliasing. Anti-aliasing creates smoother, more visually appealing graphics, but it puts a strain on your machine. In the video options menu, click on the small triangle next to the anti-aliasing box. In the drop down menu, bring it down to "no anti-aliasing" for the best performance.
Lower the texture filtering. In the video options, there is a box labeled accordingly. The level is represented by numbers. Reduce the texture filtering to the lowest number possible for maximum results.
Reduce texture and shadows. On the far right side in the video options, you will see boxes labeled "Texture Quality" and "Shadow Quality." The texture quality options range from high to low, while the shadow quality can be set anywhere between extremely high and low. Click on the small triangle next to the setting and select "low" for both in the drop down menu.
Adjust the detail. There are several options for lowering the level of specific details in the game. In the middle of the video options screen you will see the following: unit detail, building detail, vegetation detail and grass detail. You can tweak them individually by clicking the small triangle next to each box and selecting "high," "medium" or "low." Low will give you the most improvement, but you may find that you can keep some levels higher than others.