From my Snow Leopard partition, I started up the OS X Lion image to install (I was hoping to do a simple upgrade on my main partition- stupid, I know). The computer restarted and the Lion Installer began and prompted me to choose a HD to install to, but my Macintosh HD did not show up. So, now I am unable to boot into my original Snow Leopard OS. The only options I have are "OS X Installer" and "Windows HD" when holding down the option immediately after starting my iMac. It seems as if OS X Installer has replaced my original "Macintosh HD." My files are still accessible by booting into Windows. Is there anyway I can unmount the OS X Installer and boot into my original Snow Leopard partition? I've tried inserting the Install disc that came with the computer (Leopard), but it does not recognize Macintosh HD, so I can't install it. Any solutions or thoughts?