Here is the dumb mistake i made and need help fixing. I got the new iMac with the Intel i7 and ATI card. I wanted to put windows 7 on a second partition but messed up bad as i erased my mac partition when i was in the windows installer. My imac wont boot from the leopord dvd as i can choose it but it locks up right after i click on the snow leopord dvd icon. I tried to boot from an external hard drive that was formatted from another mac with snow leopord on it and the guid partition is correct. same with a usb drive as it see it but locks up after clicking on it. Anyone know why i cant reinstall? Please im kind of new with mac and really need some help. Thanks gary p.s. I tried the option key and pressing c at start up with the dvd in and it can see the install dvd but wont boot into it.