It is not possible to install Leopard on early G3 iMacs - Leopard only has G4 and Intel code.
There were G4 iMacs produced between about 2001 and 2003 on which Apple did not support Leopard installs because of their 'slow' processor - this restriction can be overcome.
My original Leopard DVDs are double layer and hence they cannot be read by some drives.
This is an intel iMac (August 2007). The discs are a grey colour and the number is 2z691-6150-A.
I am basically trying to wipe the hard drive and 'zero' before I sell the iMac. The iMac reads the install disc when I view it normally it just will not boot from it..... strange.
I do have an external hard drive but how do I make it bootable?
yes a few months ago i tried to do the same as what I am doing now... and the Disk worked then.
When i go on Disk Utility I have 232 GB capacity however 187 GB used, I know I do not have 187 GB worth of files so i think this is another partition and I am currently on an internal boot partition or something?
Disk Utility however only shows the partition I am currently on.... how do I get back to original manufacture set up?
Good to hear, if you still have space problems...
How much free space is on the HD, where has all the space gone?
OmniDiskSweeper is likely the easiest/best, and is now free...
And if needed, you can use Terminal to run it in admin mode to see files/folders your user can't see...