Get a hold of the operating system installation CD's. You're going to need them in the future anyway for erasing the HD and doing reinstalls. Get the OS 10.3 CD's. 10.4 is too busy for the G4's processor speed; it'll make the fans run all the time.
link me tto where i can buy the cd's
If you don't have this disk, then your best bet is to buy a copy of Mac OS X, even though you already have the OS installed on your computer (you could try calling Apple (800 SOS-APPL) and asking for a replacement boot disk too). Another smart way to accomplish this: look for Mac OS X on eBay.
Get a hold of the operating system installation CD's. You're going to need them in the future anyway for erasing the HD and doing reinstalls. Get the OS 10.3 CD's. 10.4 is too busy for the G4's processor speed; it'll make the fans run all the time.
I have a G4 PB, 10.4 doesn't cause much fan action for me.