Currently Being ModeratedMar 18, 2013 7:08 AM (in response to LewisHi)
Your MacBook (Air?) is acting like the shift key is depressed all the time. The safe boot confirms this, as holding the shift key down is what causes safe boot to happen normally. For that reason this is very likely a hardware issue.
Contact Apple using www.apple.com/support/contact if you are in a country that supports it or call the appropriate phone number on this page. Alternatively carry the MacBook in to an Apple retail store or service provider. If you are still under warranty or have an active AppleCare plan you should be covered, assuming there was no abuse of the machine.
Best of luck.