I have an iMac 24-inch (early 2009, designated 9,1) and have successfully installed Win 7 Home Premium 64-bit using Boot Camp. I say successfully because the installation went rather haywire, running 3 back-to-back cycles of installing the system without any intervention from myself (at one point, there were TWO Win 7 installations in the NTFS partition, one of which disappeared later). When I saw that this was going nowhere, I stopped the installation at the beginning of the 4th cycle and instructed the computer to Shut Down. On power up, I was confronted by the pleasant surprise of Win 7 loading and running smoothly on this iMac, with apparently (almost) all compatibilities taken care of (keyboard works, mouse works, DVD drive works, etc). The computer boots every time directly into Win 7; no sign of Apple Mac OS. Although this model seems absent from Apples compatibility list for running the 64-bit Win 7 version, Win 7 is cruising along smoothly and is quite fast to boot. I keep my fingers crossed. But there is no sound. The mixer indicates that the speakers work (the sound levels go up and down) but there is silence listeners experience. This is an iMac that I re-constituted by installing the latest copy of Snow Leopard by wiping the hard disk clean. I went back to the OS disc and under Drivers and installed the Apple Software Update, although I found no audio drivers for Win 7 64-bit. Under Device Manager, the audio is seen as High Definition Audio Device. Theres no info which device this is exactly. I have googled the issue to no avail. Do you have any ideas that can help? They will be greatly appreciated.