Windows 7 installation doesn't work and I can't go back to Mac OSX.

I tried to download windows 7 but right after it says "setup is starting" it's says "a required cd/DVD drive device is missing..." And I click ok and it says "no device drivers were found. Make sure the installation media contains the correct drivers, and then click ok."

The thing is that I don't know where to find theses drivers and I can't even go back to my Mac to use it, or even eject the installation disk.

Please help! I've been at this for hours.