Can't install OS9 on iMac DV

Question

My current iMac is getting old, so a friend of mine gave me a replacement one with a blank HD. Being computer illiterate I followed the instructions on the old Install CD that came with my current machine. I clicked on Clean Install and after it was through, did a restart. The new machine said that installation was successful, although most of the items under the Apple Menu are now gone. Also, it would not let me eject the Install disk, insisting that the install disk WAS the Operating System. I had to force the disk to eject via a paper clip stuck into the slot.
What the heck is going on, and what should I do (other then toss the thing in the trash) ?
I'm computer illiterate, so keep your answers non-technical and understandable. Simple instructions, please

Answer 1

Philip
Control Panels are usually kept together within a subfolder in the System Folder. Because they are frequently used, they are, however, made readily accessible through Apple::Control Panels. (There are, of course, exceptions to that generality, but they make themselves apparent when they occur.) The path for Startup Disk is therefore Apple::Control Panels::Startup Disk.
When a CD is the current startup volume it is effectively 'in use' even when it is not being read. Some part of its contents will always be in System memory, so application files on it will notionally be 'open'. The system has an inbuilt constitutional objection to ejecting a volume with open application files, and will tell you so. Normal ejection needs that files be closed, folded and put away neatly. A startup CD finds it difficult to be the agent of its own ejection. This is in contrast to, say, a plain data CD that is being read only at need. Use of the emergency release mech. is best confined to when the iMac is shut down, using Special::Shut Down..., so that all housekeeping is performed in orderly fashion. Then the CD-ROM drive, having been deprived of all sentience, and being no longer on guard against improper ejection, will let go gracefully. In the present case the CD should have been ejected during restart from the hard drive. I doubt that your action will have damaged the CD-ROM drive irreparably, but it would have more-than-ruffled its brow at the time.
eBay is only one of a number of possible sources of a 'full install' CD, in well-worn (avoid) to near-new condition. I cannot tell you the part number of the North American English CD for OS 9.1 (unless it be 691-2748-A), but that for OS 9.2.1 is 691-3334-A. If you can avoid it, do not settle for iMac machine-specific OS 9.0 Install (orange), for OS 9.0.4 Install (grey), for any non-white CD labelled 'Restore', or for a full install version less than OS 9.1. You can expect to pay between USD10 and USD50, depending on the CD's condition and the intensity of competition at auction, or on the fixed price at a bricks-and-mortar emporium.
Your 'new' Mac's hard drive presumably has some kind of System Folder on it as a result of your previous installation. When you have your brand-spanking OK OS 9.1 or 9.2.1 full install CD, it will be cautious of you to trash the previous installation, using your install CD, before making a new installation.
The extras in the Apple Menu of your 'old' machine will have to be transferred to your new machine if they are not amongst the new installation. Before you go to that trouble, however, it will be as well for you to ensure that those extras are useful to you.
Apple IIe; 68K: 11DT + 4PB; PPC: 5DT + 3PB; G3: 6DT     System 6.0.8 to OS 10.4.x