I have an Intel based iMac 20". I had a different problem. I installed Windows XP using bootcamp. After installation. To give it a try I just put Vista DVD(I have vista DVD also, but it is damaged.) into drive. After loading bootfiles vista installation asked me to reboot the machine. Here I got the problem, as the dvd is damaged, it is unable to proceed furthur, I am able to see only a blinking cursor for ever. I wanted to eject the DVD and boot either from Mac OSX or WindowsXP(Which is previously installed and working fine). One more problem here, I have wireless keyboard and mouse and I am unable to enter boot options anyway. Please give me a solution for this problem.