Why won't my eMac run OS X?

Question

I bought an older eMac from someone and tried to install OS X (it had OS 9) but the installer quit and said "the installer has unexpectedly quit (error 1)" . what does error 1 mean? I thought it didn't have enough RAM so I ordered 1GB, installed it, but OS X still won't install. And now when I turn on the computer it tries to run OS X but freezes and a little bow with some text comes up in the upper left corner of the monitor.
Does anyone know what the problem is or what hardware I might update to fix the problem? Here are the specs:
iMac version 1.2.1
CPU: PowerPC,G4 @ 800 MHz
Cache: 256 K L2 @ 800 MHz
1 GB of RAM
32 MB VRAM

Answer 1

The same version of Apple Hardware Test was used for some eMac and iMac versions. It's been a while since I ran AHT, so I don't remember if it says eMac or iMac, but you're certainly describing an eMac.
What color is the label on the OS X Install disc you were given when you bought the eMac? If it's a retail (black label) OS X disc, it should have the version number on it (e.g., 10.1.4, 10.2.2, 10.4.6, etc.). It it's the model-specific disc that originally shipped with the eMac, then there's something about the OS X version number and "eMac" in very tiny print on the label.
It's possible that the seller gave you the original OS X disc that came with the eMac, but that at some time the original owner upgraded to a later version, say from 10.2.x to 10.4.x Because of changes introduced to disc formatting with OS X 10.4, you can't go back to an earlier OS X version without doing an Erase and Install. Or, if the original OS X disc is for the 10.1.4 taht came with eMacs during the first few months on the market prior ro the release of 10.2, one of the missing features in 10.1.x was the ability to do an Archive and Install --- the only way to reinstall 10.1.x is to erase the hard drive and start from scratch.
If you don't have the Applications CD that came with the eMac, an Erase&Install could prove troublesome. You may want to consider investing yet more money into your purchase, and get the Tiger OS X 10.4 retail install disc. My own experience is that a first-generation 700 MHz eMac with 640 MB RAM is still respectfully quick, especially running 10.4, which is much more responsive that 10.2 or earlier. Your 800 MHz eMac with 1 GB of RAM should do quite nicely running 10.4. You can use the tips in Gulliver - Tiger Upgrade Guide.
One possible complication: some early eMacs came with a CD-RW or CD-ROM only, with no DVD-ROM or DVD-RW ability, and Tiger 10.4 is only sold as a DVD. Apple used to have an exchange program where for something like a US$10 handling fee, you could exchange the Tiger DVD for a set of CDs (7 or 10 CDs, or something like that), but the website offering the exchange program has been taken down after the program had been extended six times. There have been reports of users successfully getting the CD exchange by calling the Apple Store and getting a live operator, then asking if there were any copies of the CD exchange set still available --- Apple had some sets left in the supply chain when the exchange program finally ended, and they were unofficially still available a few months ago at least.
Or you could pick up a Firewire external DVD-RW drive for around US$100 and boot the OS X Install disc from that using Startup Manager.
p.s. Welcome to the Apple Discussions!