I've been working to install create a bootable usb drive from my buddies Mac. I torrented Mountain Lion (yes, I know this is unethical, but I didn't want to spend money on a setup I wasn't sure of) I had some troubles messing around with the .app file, I managed to do some digging around and found a terminal file in the .app I accidentally executed. His computer was fine and I walked away for thirty minutes. Came back, tried to move the mouse and now it's throwing a Kernel Panic 0x0043913F. He had 10.5 on his iMac (I found out this is why I was having such a miserable time.) and I think I may of updated his system? Is it possible to do a rollback? Post if any you need any clarification. EDIT: I've read here that I need to reinstall the OS. Is this possible with only a PC at my disposal?