I just inherited an original imac also. I want to set it up for my 9 y/o niece-a great first computer.
However, I just turned it on for the first time and realized it has 8.1 installed. I ordered a bunch of education software from software-blowouts.com- and most of the software requires 9.0 and above.
I own a 9.0 (don't remember if I purchased it retail or it came with an older computer) and 9.2 CD's. I tried starting up from the 9.0 CD and it told me that I needed to update my computers firmware. I tried using the same CD and the update firmware app in the extras folder. I got an error saying that the update only works on G3 powermacs.
Not sure what to do next. I've searched apple's site for the firmware update but no luck so far.