iMac Snow Freezes During Startup

Also, I did make sure that the hard disk that contains the system folder was selected in the Startup Disk control panel. I selected it. . . still the iMac would freeze at startup.

I then ran disk first aid. Supposedly there was a problem called "Invalid BTree Header, 0,0". I hit repair and it repaired it successfully (well, I'm going by what it said at the end of the repair). The iMac still won't start up, though I'm not sure if that BTree Header problem had anything to do with the computer freezing at start up.

Now I'm running the Zero All Data. If this doesn't work, I promise not to touch the computer until someone has given me advice or help that is more reliable than my (so far wrong) hunches.

Thanks again!

Well, I just finished with the Zero All Data, and at the end it said "Initialization failed." SIGH Afterwards, I reinstalled OS 9 and restarted. Now, I have the dreadful flashing question mark folder popping up when I boot up. From there, it will automatically boot up from the cd. I tried running Disk Aid and it froze on me. Restarted, tried running it again, and it froze. I REALLY hope I don't have a bad harddrive. I had to replace the harddrive a few years back, and I can't afford to replace it again.

Any suggestions?

It's an iMac Snow G3 (Summer 2001 model)

I'm completely baffled with what's going on. I was able to boot it up after installing OS 9. It worked fine and I configured it. I was excited and thought I had finally made a break-through.

Afterwards, I decided to upgrade it to OS X (Tiger). I know that it works on this computer because this is the operating system I was using before I reformatted the hard drive. 75% through the Tiger installation it froze. I restarted and tried again. Froze again after about 30%. I restarted and checked my disk. Ran a repair but nothing needed to be repaired--supposedly the disk and everything else was fine. So, I tried again. This time, it stopped 60% through and said that there was an error and couldn't install. I figured, what the hey, I'll try once more. Now, prior to the 4th try, I had been doing "erase and install." This time I figured I would just click on upgrade and see if that worked instead. 50% through a transparent box came up telling me to restart my computer. At this point, I sighed and gave up. I ejected the cd and it was hot. . . so I'm wondering if my problem could be that the computer is overheating? Also, I know that it isn't the disk because before installation it ran the installation disk check, and it came out clear.

Now, however, I once again cannot start up the computer because the flashing-question-mark-folder appears. Apparently, then, I have no finder.

Could this problem be from the computer overheating? Or will I need to reformat it again? Or is it something else that I'm completely overlooking?

Any suggestions are appreciated and welcomed. I need, need, need this computer up and running soon.