Macbook

I need help on my mac. The problem started when I cannot reboot my mac from leopard os. Once I turned on my mac, the apple logo comes up and spinning wheel comes up as well but it does not go to the mac screen login screen. I tried a variety of solutions to no avail. I came to the conclusion that I may need to reinstall everything on mac. I used my mac os installation disk to reinstall. Once I got to the prompt for reinstallation, i both chose archive and install & erase and install. However, i wasn't successful. During the installation process, it said i needed to clean my disc and restart my mac. Although the disc wasn't dirty, I cleaned it nonetheless. I tried reinstalling but the same result came up. I then went to disk utility to erase my hard drive to ensure there are no problems that may arise from hard drive sectors which i believe to have been the root of my problems. I chose 7 pass erase options. After it was done, i tried to reinstall mac os but i cannot since the startup manager does not recognize my mac hd drive and it only recognizes the windows system on my mac. If i try to start the regular way, it only show blinking folder icon with question mark. Any help to get my mac working again will be very much appreciated