So today I was simply browsing the internet when I got the lovely rainbow pinwheel. Usually this goes away after a couple seconds, but it stayed put to the point that I had to restart my computer (I have an Intel iMac btw). When I restarted I got the lovely flashing folder with the question mark. Upon further research, it appears OS X cannot find the startup files. I put in the 10.5 upgrade DVD my iMac came with and ran disk utility. To my great displeasure, I find that my hard drive isn't even listed! The only thing listed is the DVD drive and the disc. I waited 15 minutes to see if it was still checking my HDD or something, but to no avail. I tried CMD + OPT +R +P (reset PRAM etc...) and that didn't work either. I unplugged keyboard, mouse, etc... nothing. Computer is only 7 months old. Oh, and when the computer first starts from the disc it says that OS X version 10.4 or later cannot be found so I can't upgrade to 10.5... Basically my Hard Drive is invisible for some reason. Assistance is GREATLY appreciated. Thanks.