I recently installed Windows 7 through boot camp on a friends iMac. I don't have specific details as the Mac wont boot. After a successful install of Windows, everything ran smoothly until a day or two later, finder on mac wouldn't respond. There was no desktop and I couldn't browse for files. Safari and other applications could still be accessed through the dock. Now the Mac refuses to boot at all, it turns on, plays the startup tone and displays the apple logo with a rotating circle below. Occasionally a progress bar would appear under the logo, it would disappear soon after without filling at all. I have done an SMC reset, unplugging the power for >30 seconds and a PRAM reset. The computer will not boot in safe mode or from disk when selected using alt/option key or 'c'. I'm quite sure it was running the latest version of Snow Leopard, with an apple wireless keyboard and mouse. Strangely, I can select and successfully boot Windows 7 and use it smoothly. Please advise me on what I can do to fix this. Thanks in advance! EDIT: The computer is less than a year old. I didn't think it would be hardware failure.