imac not restarting

[Charlie-Burt]

I closed all programs and restarted my imac..that is 15 minutes ago...the little gear is still spinning 15 minutes later and hasn't restarted...should I just power off?

 

[alust2013]

Hold power until it shuts off, then try to boot again.

 

[celticpride678]

Hold down the power button until it turns off.