Problem with iMac G3 running on OS 9

Hi,
I have a problem with my imac. The computer stops responding ("freezes") at the Happy Mac icon during the system startup process. There is the Happy Mac icon in the middle of the page and the page is kind of blue/grey.
I really don't know what I can do cos it doesn't do anything when I insert the Restore or Install CD.
Anyone would have an idea pls
Thanks
JMV

Try to start the Mac while holding down the Shift key. This will prevent all the extensions that are not basic to the machine from loading. If the machine then starts, the problem is an extension conflict preventing the system from loading beyond that point.

The install/restore CDs must match the computer model, or be an across-the-computer-model disk purchased from Apple. A CD meant for an iBook, for example, won't work in an iMac.

If you are certain the CD matches the iMac or is an across-the-board disk, load the CD, if possible, and try to start the machine while holding down the C key. Holding down the C key should force the machine to start from the CD.

If the system boots with the extensions turn off like Brown_Study suggested. Then you enable each extension one by one, until you find the problem extension. Unless you know what was the last item you loaded.