Earilaer today I was on my computers desktop gong into my Applications folder when my computer froze. Nothing worked at all so I held down the power button until it turned off. I then waited about 5 or so minutes to turn it back on. I turned it on and I got to the greyish screen and the apple logo came up. During this time the fan was loud and on but turned off. Usually it stays on for about 30 seconds after I get to my desktop. I turned it off again the same way as before but this time I turned it on and the computer got only to the very first white screen. The fan did the same thing as before and nothing else happened. There is a disk in my drive, I think its some type of old game or a CD so I can't put my start up disk in there. I tried holding down my mouse when I start the computer to get the disk out but nothing happened. Im not sure what to do. I don't have Applecare. So does anyone have any ideas as to what I should try? My iMac is a 24" Intel Mid 2007. I apologise in advance if there is already a thread on this. I serched but came up short. Thank you everyone for your help!