DELL Vostro 1700 WINDOWS XP (Laptop) There's no START Button showing in XP

Hello there, 

   My first posting on this Dell Forum.. I've got a Question, My Dell Vostro 1700 is 7 years old & today i've got a Problem on it, It starts up and does log me onto the Screen which say either your name or another users name for Windows XP log in I go to click on my name today it loads into Windows but there's no START bar or bar underneath & non of the desktop apps are showing - What is the problem please HELP Me!!

Thank You