Did you make any changes yesterday?

Try unplugging the network cable and safe (shift) booting. You may have to wait 10 minutes it takes longer to safe boot.

What happens?

If you are running OS X, try booting in Safe Mode (hold down shift at boot, until the spinning gear starts). Login to an admin account and turn of web sharing in System Preferences. Reboot normally and see if this resolves the issue.

I think the most likely culprits are a failing hard drive, or the bad capacitors problem that struck the first models of G5 iMac and the G4 eMacs.

First the hard drive. If it's the stock drive, it's a prime candidate for failure (most drives last 3-5 years; think of them as consumables, like light bulbs.) Unfortunately the SMART status used by Disk Utility is next to worthless for the most common failure I see, bad blocks (sectors). If you go to versiontracker.com and download SMART Utility, it will let you launch a few times as a demo. SMART Utility reads the SMART attributes of a drive directly and will tell you if your drive is suffering from a failure or imminent hardware failure. Of course, you'll need to boot to an external drive for this. SMART attributes can only be read on an internal drive, so putting your emac in Firewire Target Mode and connecting it to another Mac will not work in this case.

Second, the caps. Your symptom is actually more indicative of the hard drive problem, but if you get your computer booted and it freezes, shuts off, or has video artifacts like lines across the screen, then it could be the caps. If you're comfy taking it apart (no mean feat with an eMac, the bitty power cable is a bear to plug back in) you can examine your caps for bulging and leaking.

Did you try resetting the PRAM? Hold down APPLE OPTION P R when you start up, let it chime through a couple times, not just once... see if it resets the settings and lets you boot naturally.

IIRC SystemStarter[67] is an error code for local host. Have you run permissions and repair for your eMac?

Will it boot from an external dive with a good OS on it? If so, sounds like it is time to do an archive and install...

If you can boot from an external drive with a good OS run the disk utility. With the disk utility you can check/repair permissions and run disk repair. (files not mechanical). If no joy I think David is correct--time to reinstall your OS. Ralph

Hold down the option key when you reboot with the external HD plugged in, and it'll show you the drives and just select your external. Simple and easy.

I had the same problem and replaced all the capacitors that had burst. Took some time, but was fun and gave my daughter a free eMac.