Education problem one moment please ... in mac appstore

First, the path Application / Utilities and go to open Disk Utility:

The Macintosh HD from the left window and select Repair Disk Permissions I click and wait to be Compelete:

Now you need to Restart your computer. After the restart, the Application / Utilities, open Terminal and go:

Now enter the following words to the terminal:

rm ~/Library/Preferences/com.apple.appstore.plist
rm ~/Library/Preferences/com.apple.storeagent.plist
rm -rf ~/Library/Preferences/ByHost/*

Now restart your Mac again ... your problem solved

thanks to ali007 for this Education

 GOOD LOCK