Q: Has any one upgraded a emac g4 to lepord if so how

First, you eMac's processor has to be 1.0Ghz or faster to install Leopard.

Second, the disk cannot be a gray system install/restore disk from another Mac model. A proper Leopard retail install disk looks like this:

Third, you need a min of 512MB RAM. Some eMacs shipped with a lot less.

Try booting while holding the c key depressed until you see a desktop. That forces the computer to boot from a system disc in the optical drive and should bring up the installer.

Do you maybe have Firmware Protectection set up?

What shows if you hold alt key at bootup?

What is the 2z691-****-A number on the Install Disc?

You can install a max. RAM of 2 GBs.

OS X 10.5 Leopard will run appreciably better on 2 GBs of RAM.

Hhere are the specs for the RAM.

You can find and purchase reliable Mac RAM from online Mac RAM vendors Crucial memory or OWC (macsales).

Good Luck!

Crucial does not recognize that eMac model's ability to accomodate 1GB Modules:

http://www.crucial.com/store/listparts.aspx?model=eMac%20(1.25GHz)&Cat=RAM

They tend to stick wth Apple specs regardless of how outdated the specs.

Go with OWC. We bought their 1GB module for our eMac 1.42Ghz about two years ago and it has worked perfectly, This is their listing for the one I bought:

1GB PC2700 DDR 333MHz CAS 2.5 184 Pin DIMM

I second that, upgraded my eMac 1.42 years ag to 2 GB from OWC, still one of my best Macs.