Go to add remove programs list and uninstall All versions of Java you find in there, then go to the link below and download and install the latest version of java. Let me know if any of them will not uninstall.
http://www.java.com/en/download/manual.jsp
Choose "Windows 7/XP/Vista/2000/2003/2008 Offline" download it to a folder of choice then execute the file to install java.
