System Preferences disappeared

[Epicc]

Hey, I'm randomly missing System Preferences from my whole computer. I haven't done anything different recently, I just realized that when I went to click it on my dock, the question mark symbol appeared and finder didn't open.
I know this is a common issue and was wondering if anybody had a fix ..
I'm running Leopard on a 933MHz Power Mac G4 (Quicksilver).
I can't find my Mac CD and doubt System Pref is available somewhere for download, but is it possible for somebody to email me it?

 

[angelwatt]

1. Have you rebooted?
2. Do you have another account you can log into to see if it works?
3. Try booting in safe mode.
4. Try opening via the Apple menu in the upper-left.
5. Also try from Spotlight.
6. If you can open Console it may have some messages saying why it won't open.