Corrupted win8 install boot loop

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?

still boots into windows

none of the startup hotkeys seems to work except for holding down the mouse button, which I did to eject the disk, which didn't work to stop the boot loop.

So I found my snow leopard install disk, and tried booting with that in. I also tries holding down C to force cd boot, but the computer insists on booting from the broken windows partition.