Hmmm, I'll keep trying to help :D. So you set the environmental variables, Your Windows XP?.... I'm flabbagastered. LOL<<<..... Try unistalling and reinstalling java, or unistalling the client and reinstalling it: Client Download: http://uppit.com/v/I9H6L34R
Mirror Download: http://www.mediafire.com/download.php?ym5guzzzmjj
Java Download: http://www.java.com/en/download/index.jsp
Choose Which One xD