Help please! 

I have an imac (late 2009) that came with snow leopard. I've tried to install 10.5.8 on this computer but it doesn't seem to be working properly. Airport isn't recognized with 10.5.8 installed.?? I used the original install disk to install snow leopard again, and the airport card is recognized. Erased & installed 10.5.8 again from (Leopard Retail disk) & no airport. ? The imac also seemed to be having issues starting up from the Leopard install disk causing kernel panic message? (your computer need to be restarted..) and having to be turned off & on again. Any advice?
I have an imac (late 2009) that came with snow leopard. I've tried to install 10.5.8 on this computer but it doesn't seem to be working properly. Airport isn't recognized with 10.5.8 installed.?? I used the original install disk to install snow leopard again, and the airport card is recognized. Erased & installed 10.5.8 again from (Leopard Retail disk) & no airport. ? The imac also seemed to be having issues starting up from the Leopard install disk causing kernel panic message? (your computer need to be restarted..) and having to be turned off & on again. Any advice?