I've a terrible problem... I was working on Windows 7 on my iMac Just browsing some websites on Chrome, and running Windows Security Essentials on the background. Suddenly I heard some weird clicking sounds coming out of the iMac. I noticed the screen had frozen. It took some minutes and then it continued again. But the second time the clicking started Windows crashed and was turned off. When I put the iMac back on it tried to start again in Windows, like I had set it up to. But startup failed, as 'no bootable drive was found'. I tried it multiple times, but it had no effect. So I decided to try to go Mac OS and see whether that worked. I got in, but I noticed the clicking sound returning and the screen freezing again, and a spinning rainbow appeared. After a few minutes Mac OS also crashed... And now when I turn the iMac back on... I see this on my screen (see attachment pls) Does anybody know what happened? And more importantly, how on earth can I fix anything?!