Hmm...I played that game on my old P4 1.6 GHz and 256 MB Ram without problems. Sure, 512 MB is recommended but 256 meets the requirements.
I think the problem is rather with the video card that may not be supported.
extract forum LA site:
Supported Chipsets at the time of release:
ATI Radeon 8500/9000/9200
ATI Radeon 9500/9600/9700/9800
NVIDIA GeForce 2/3/4 family
NVIDIA GeForceFX family
Additional Chipsets supported. For a complete list of supported 3D cards, please consult the Troubleshooting guide, or visit the Technical Support section of the LucasArts Website at
www.lucasarts.com).