OS X won't boot.... BootCamp fine?

[mahoganyjoint]

My imac was fine, until i turned it off today to move it. When i plugged it back in and turned it on, it'll stay on the white loading screen and not go any further. i thought it was a failing HDD but it cant be because my Partitioned W7 works fine on Boot Camp.

Any idea whats going on?

 

[benwiggy]

The first thing you should do is to boot to another Mac partition (i.e. installer disk or the Recover Partition) and run Disk Utility to Repair the Disk (NB: Disk not Permissions).
This will check if there are indeed any errors on the volume and fix them if it can.

If that doesn't work, then the simplest thing is to erase the volume, and restore the disk from your backup.