Uninstalling Java from Windows

1. Download the Microsoft Installer Clean Up utility file and save it on your desktop.
2. Double click on executable file. The installation process will start. Follow the instructions accordingly.
3. Once installation process is over, go to Start -> All Programs -> Run Windows Install Clean Up utility.
4. This will launch the Windows Installer Clean Up utility dialog box
   Under the Installed products list, select the desired Java version that you want to remove.
5. Click Remove and Exit

Reference: http://www.java.com/en/download/help/uninstall_java.xml