I just installed windows 8 in my 2008 iMac, and when I start up the computer, it defaults to windows. That problem is that the window on the new default partition is corrupted, and prompts me to restart to fix it, which simply brings me back to the same corrupted startup. I managed to eject the install disk by holding down the mouse button, but I can't seem to be able to use anything else. I've tried holding down a bunch of different key combos on start up, such as cmd+opt+shift+del+disk id(ie: 1). Is there anything else I could try before using another external boot drive to restore?