My iMac won't boot. Every time, no matter what mode I try booting in, it boots and stays on a blank white screen I have a problem with my iMac. When I tried booting it, the loading bar went half way, slowed way down, then about 20-30 min later, the bar had gotten all the way to the end... But it stayed on the booting screen. So I forced shutdown my computer, then tried booting up it again. But it didn't even try to load. It just showed a blank white screen. No text what so ever. I tried many different methods to fix this, booting in safe mode, single user mode, reset nvram, recovery mode, etc. But every time I tried any of these methods, I would still get a blank white screen. I am at a loss. I can't even try to reinstall the OS if I wanted to since it only boots to this white screen. Does anyone know how what I can do to fix this? (I believe my computer is a 2010 iMac, if that helps)

Quick Update: I just tried booting it while pushing the power button + option button. Even though the screen is still completely white, now the mouse pointer has shown up on the screen and I am able to move it around. But not sure if that indicates something or not.
Try to boot up using Cmd + Option + P + R to reset the PRAM.

Also try booting up with Cmd + R for recovery mode.

It seems likely the main hard drive has failed.

If you can boot up into Cmd + option, you will be able to boot into a Boot CD or other recovery disc/USB drive to help restore your main hard drive.