I don't know much about macs i was raised on windows but have a macbook and iphone now and my next comp will be a mac, but since I don't have much experience this is pretty tough. This problem is with a friends Imac, who asked me for help. Replace one macbook screen and everyone asks you to fix their computers... All of a sudden, his Imac(its a few years old, probably) which is running OSX 10.4.8 goes into a kernel panic on startup. I have tried the following things: Apple Hardware Test from the OSX 10.4.8 disc showed no problems. I tried running the extended test but it finished really quickly, perhaps I should try running this over and over? I tried to run the disk utility but when I hold C down on startup it does not go to the kernel panic screen, it just goes to a blank light blue screen indefinitely. Also, I cannot boot into safe mode by holding down shift on startup, I still get kernel panic. I have held option down and tried to choose to boot from the hard drive or the osx disc and though it does try to read the disc and load for a minute but then always panics. Because I can't even get into any settings of the computer I don't know any specifics about the processor or ram etc since my friend doesn't know much about computers. I have succesfully cleared PRAM and NVRAM but this did not solve the problem. Is this a hardware issue? What are my next diagnostic steps?