The newest version of JAVA is 7 update 51
1. To update Java:
Windows XP: Click Start > Settings > Control Panel
Windows 7 and Vista: Click Start > Control Panel
Type Java in the Search Control Panel located in the upper right corner.
2. Launch the Java Control Panel by double-clicking on the Java icon. The Java Control Panel appears.
3. Click the Update tab to access the settings - If you don't see the "Update" tab please visit http://www.java.com/en/ or call the Help Desk
4. Click Update Now
You can uninstall older versions of Java manually in the same way as you would uninstall any other software from your Windows computer.
Older versions of Java may appear in the program list as J2SE, Java 2, Java SE or Java Runtime Environment.
Windows 8 - Uninstall Programs
Windows 7 and Vista - Uninstall Programs
Windows XP - Uninstall Programs