I´ll bring it to you short and painless:
Forget it with that system. It just won´t run with an acceptable performance.
What you need is:
Windows 7 64 Bit (!!!).
Graphics card with 1Ghz GPU and 2 GB VRAM.
Your CPU would probably be good enough, same for the ram. But if you want to upgrade, I think that a completely new system would make more sense.
Sorry to bring that to you, but CloD never played on 32bit-Systems. What´s more, the system-requirements printed on the box are just way too low. This was messed up with the release of the game.
I´m sorry for you and hope you will be able to play the game with the next system you will buy. If you need any advice with getting new hardware, I would post here:
http://theairtacticalassaultgroup.com/forum/forum.php
The hardcore cliffs of dover-players are all there.
Good luck, and again: I´m sorry for you...