Safe Boot, (holding Shift key down at bootup), run Disk Utility in Applications>Utilities, then highlight your drive, click on Repair Permissions, reboot when it completes.
(Safe boot may stay on the gray radian for a long time, let it go, it's trying to repair the Hard Drive & clear caches.)
Then move these files to the Desktop for now...
/Users/YourUserName/Library/Preferences/com.apple.finder.plist
/Users/YourUserName/Library/Preferences/com.apple.systempreferences.plist
/Users/YourUserName/Library/Preferences/com.apple.desktop.plist
/Users/YourUserName/Library/Preferences/com.apple.recentitems.plist
Reboot & test.