Computer to run Star Wars Knights of the old Republic

I purchased a computer system yesterday consisting of...

What I assume is an Intel P4 3ghz
listed as Intel 2.93ghz LGA775 533m

Intel 915GAVL ?Prescott? Motherboard...
c/w HT Technology

I had the choice of a ATI X300 Radeon 128 MB Video Card or to upgrade?!?!?!
to Graphics Media Accelerator 900.. I took the latter. Seems to be a
onboard Intel system...

1G Kensington DDR 400 mhz 2.5v ram...

Windows XP Media Center

I purchased it to run star wars knights of the old republic. It ran fine
the first time I ran the game.. but the next day when loading the file to
play.. the game shuts down returning me to windows.

I've tried loading the latest driver from intel for the graphics.. I've
increased the page file size.. I noticed that when using the system
resources in the task manager.. the cpu is at full usage prior to shutting
down...

Suggestions? A new graphics card? A different machine?

Scott.