Note:
If the normal uninstallation process (as mentioned above) fails, then please try Microsoft Windows Installer Cleanup Utility. This tool will ensure that all irrelevant Java Runtime Environment Microsoft Installer (msi) registries are removed. Detailed information and download is available at: Description of the Windows Installer CleanUp Utility
Removal instructions:
Download the Microsoft Installer Clean Up utility file and save it on your desktop
Double click on executable file. The installation process will start. Follow the instructions accordingly
Once installation process is over, go to Start -> All Programs -> Run Windows Install Clean Up utility
This will launch the Windows Installer Clean Up utility dialog box
Under the Installed products list, select the desired JRE version that you want to remove
Click Remove and Exit