How to install Leopard on HP6730b(Intel Core 2 Duo, 2GbRAM).... I'm so tired i can't install...

HP6730b
Intel Core 2 duo 2.2Ghz
RAM 2 Gb

I installed iDeneb v1.6 10.5.8 Lite Edition and when install processing after about 15 minutes show next message:

Install Failed, Mac OSX could not be installed on your computer. The Installer could not validate contents of the 'Leopard_Installer' package.

Also i installed Snow Leopard 10.6.1 and 10.6.2 when installl processing show that message....

Install Failed, Mac OSX could not be installed on your computer. The installer could not install the software because there was no software found to install.

Help me please...