Disconnect all usb/ and or other drives.
Connect your power cord

Go to applications/utilities/click on disk utility.app.
At the top of the open window select your hard drive
Click repair disc permissions. This will take a few minutes.
Restart you computer. See if this helps.

__________________
"What you hear in a great jazz band is the sound of democracy. “The jazz band works best when participation is shaped by intelligent communication.”
Harmony happens whenever different parts get to form a whole by means of congruity, concord, symetry, consistency, conformity, correspondence, agreement, accord, unity, consonance…….