I am trying to install tiger on my G4. But I can't start the installation because it says that I don't have the right operating system. I am running 10.2.8 right now. I'm I screwed because I never bought 10.3.
Did you purchase the actual Mac OS X installation CDs/DVDs or did you get the Mac OS X upgrade CDs? The former will allow you to reformat the Mac and do a fresh installation, while the latter will simply upgrade the currently installed operating syste to the one on the upgrade media.