How to factory reset an eMac?

Hi,

If it is merely a question about erasing the hard disk, and if system discs cannot be found, you could try to burn a CD-R (or DVD) from an appropriate free Linux PowerPC download (ISO file). This could possibly be something like an old Ubuntu live CD (maybe 10.04 or earlier) if it can be located (https://wiki.ubuntu.com/PowerPCFAQ).

There was also an early PowerPC version (dban-2.0.0_powerpc.iso) of a wiping utility called DBAN on a bootable Linux CD.

eMacs are too old to have a Recovery partition (the command-r thing). YOU really need the factory install/restore CDs/DVDs that came with the computer or a full retail install disk set.