Wiping Back To Leopard

[appleimaclover]

Hi guys,
I bought an imac 2 years ago, and updated it to leopard when that was released.
I no longer have the discs i used for Leopard, only the original mac os x 10.4 discs.
I am very soon going to be selling this machine and need to wipe everything so that all is left if the operating system in the form you would expect as if you had just bought a new mac.
How can this be achieved, i tried disck utility> erase, but only erase free space was 'highlighted'.
Cheers,
AIL

 

[r.j.s]

You insert the gray disc, then restart, holding C during the boot process. Once it boots from DVD, you'll be able to Erase and Install.

This process, since you lost the Leopard disc, will only install Tiger. You'll have buy Leopard again in order to install Leopard.

 

[jackiecanev2]

Wirelessly posted (BB 8900: BlackBerry8900/4.6.1.250 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/301)

If you try and do a manual wipe of everything you will not make it like if you "just bought a new mac." You need to reinstall the OS, and you will have to have the discs for that. There is no getting around that part.