installing leopard on powerpc g5.. help please!!!!

hi all. ok i recently brought an iphone 4, when i connected it to my itunes it would't work cos i needed to be on 10.5. i currently have a 'DUAL 2GHZ POWERPC G5' processor running tiger 10.4.11. i just brought an 10.5 leopard os x install disc & when i try to load it it had 'exe' files. obviously i know they are windows based files & cannot be run on a mac unless i have a intel based processor. but is there any way i can load a program that will allow me to run the leopard 10.5 install disc on my powerpc 10.4.11?

iv treid to install crossover, darwin but they won't support my old *** computer lol.. it's p****** me off!!! arrrrrrrgh!!

or do i basically need to get a brand new mac?

Your G5 will run leopard just fine, heck, most G4s will still run leopard. If the discs have an .exe file on them, then you bought something that wasn't what you were promised. Search Amazon for Leopard and buy from a reliable source.

FYI, .exe files are Windows files and won't run on an Intel Mac unless it has Windows installed. It has nothing to do with the CPU in this case.