Hi, I just bought this iMac from a surplus retailer and I was informed it would be an as-is purchase but maybe yall can help me out? I'm really new to apple also so bear with me. When I boot the computer, it boots into a Windows XP version with a ctrl-alt-del style login. So I got a copy of snow leopard and I wanted to clear the entire hard disc and re-do everything with only snow leopard being on there, but absolutely none of the startup keys that i've tried have worked, ie. holding C, pressing option after startup, etc. Nothing changes it from booting up the copy of Windows XP. Here's exactly what happens. I press the power button, a solid blank white screen appears for a few seconds, the iMac chimes, and then it boots into Win XP. Can anyone give me any advice on how to re-install a different OS? Much thanks!