27" iMac Shutdown problems

[TheHoffman]

Hi guys,

Recently whenever i have tried turning off my 27" iMac it does to the blue screen and stays there, normally its resulting in me having to hold down the power button or switching it off at the socket, either way when i next boot it up it says it didnt shut down properly. I left it last night to see if it was just taking its time but it stayed on the blank blue screen for over 4 hours before i gave in a switched it off by the socket.
Please help!
thanks

 

[Hellhammer]

http://guides.macrumors.com/Mac_doesn't_boot

Try those steps, I'm too lazy to write them again

 

[TheHoffman]

This is if mac doesn't boot but non the less thank you for the help, to fix i just had to go to disk utility and repair. thanks again!