Currently Being ModeratedSep 30, 2013 7:26 AM (in response to fatima55)
What model Macbook?
Click on Apple Menu choose About this mac
Open Apple Menu>>>>Software update (do all of your updates first)
Reset PRAM, (Click this link)
Reset SMC (Click this link)
Also try opening Disk Utility
select your Macintosh HD from the left hand sidebar and repair disk permissions.
Get back to me.