Real Time Strategy

[Deeceem]

Star Wars: Empire At War (preferably with the Addon).

Basically you have a galaxy map where you deploy/build/shift troops and buildings and then send them to attack. Once in battle you have quite a similar playstyle to company of heroes - an action oriented - with a reinforcement system based on how many troops you sent to attack, with capture points who define how many troops you can call at once.
If you get attacked the buildings you have on the planet/orbit are also on the planet/in the orbit and can provide you with the opportunity to build upgrades for instance, but are already built and there cant be built buildings in combat (besides some turrets/repairstations etc. via specific capture points).
What I always liked is that you have basically two different army sets for combat on the planet and in the orbit and which can affect each other.
For instance you could sneak a little strike force directly on the planet even if the orbit has an enemy fleet deployed and try to take out an Ion cannon on the planet, which otherwise could be used, when you attack the orbit. Other way around if you have established your fleet in the orbit of an enemy planet you can call in bombardements in ground combat.

I remember I could run it with low details on my old crappy Notebook, can't say if it would run good enough for your needs on your machine though.