24 inch iMAC boots to the login in screen after entering the password the login in status bar will briefly appear s then will go no further than the star screen

my 24 inch iMAC boots up to the log in screen after entering a password the logging in status bar will briefly appear then the screen goes to the star screen and is frozen there until you power it down. I tried to boot with the disk and got into the disk utility and did disk and preference verifying and repairs but now I can't get there with the disk anymore is this a simple fix or a HD issue. My disk is almost full and have a time capsule