[ubuntu] trouble logging on

view story

http://ubuntuforums.org – I am a new ubuntu user.A while my account when i logged on only showed the background,ie no icons.So i logged on as guest and it worked .I finally got tired of logging on as guest.and clicked the white square in the upper corner of my logon name.It said something like rebuild desktop i believe.Now it is a black screen with only my login id-VGN-NW240F:$ Any body know what i need to do to recover my desktop? (Hardware)