> First you need to remove previous Java installed on your computer.
In Control Panel for Windows, go to Add/Remove Programs (Programs and Features for Vista), scroll down to find and remove older versions of it.

> Then, you need to install Java 7.
Click here and download Java 7. If you have Windows 64-bit, then select Java 64-bit otherwise select Java 32-bit. Java is updated after the installation process is completed.