Insert DVD containing Mac OS software into system drive. Reboot system. Confirm installation and agree with license. When prompted to select drive, select disk utility from menu bar. Select hard drive and click on erase button. Select Mac OS extended file system. Confirm erasing all data. Once drive formatted, close disk utility. Select to install in hard drive that was erased. After installation completes and system reboots, select Language and Keyboard for your country. When asked if already own a Mac, select to transfer your information from another volume in this Mac. Select to transfer user data. Once complete and system reboots, your Mac is ready to use.