Unfortunately there is a few things that stop it from being good for modern games. The main things being the 4x AGP slot and the maximum memory of 512MB (of PC133 RAM). I'm not saying it wont be possable to run Rome total war, but it will be extremely choppy. At minimum settings you might be able to get away with it.
Minimum specs for the game say: 256 RAM and pentium 3 or equivalent and a 64MB video card.
Here is a few
AGP 4x Cards
and here is the compatable
RAM
What processor does he have?