I use an iMac G3 for games, but it definitely has problems, including a Sherlock 2 alias which refuses to run from the Apple menu (despite the alias being up-to-date), choppy sound (not found in Classic Environment), a partitioned hard drive, and a few others. See, around 2002 or so, the hard drive died, and when it was changed, the hard drive was partitioned, with a Mac OS 9 side (about 2GB) and the Mac OS X side (about 18GB?). The Mac OS 9 side was sort of messed up, with things removed deemed not necessarily (my brother and father's handiwork). Even after an upgrade to Mac OS 9.2, it still has problems. Choppy sound? Yes. A strangely jumpy mouse whenever the Mac OS X partition is opened? Yes.
What I want to do is not merely delete the hard drive and start over, but really start over. Make the iMac new again (well, not really). You know, with the "Welcome to your new iMac, want to get on the Internet?" dialog? YES, that one! How would I go around to doing it? (and assume that I found the original boot disc).