When I turned on my PowerMac G5 Quad today, I saw it boot up into this screen where there is a folder with a question mark. I restarted and nothing helped.
I will boot from Mac OS X DVD and will follow the instructions it says. Thanks for the help.
Edit: I repaired the startup disc and reselected Mac OS X volume. Now the PowerMac G5 works like a charm. Thank you for your help.