do you mean in add remove programs? you should only have the latest version located there if that is what you meant, having old versions is a huge risk to your security. Now the newest version will remove the previous version but you do have to remove all the other old versions manually. JavaRA is an excellent little tool that will do all the hard work for you.
Download JavaRa and unzip it to your desktop. (at bottom of this post)

* Double-click on JavaRa.exe to start the program. (Windows Vista users Right-click JavaRa.exe > Select Run as Administrator)
* Click on Remove Older Versions to remove older versions of Java.

Then download and install Java SE Runtime Environment (JRE) 6 Update 16.

Download Link: Java SE Runtime Environment 6u16
Java SE Runtime Environment 6u16

Note: UNCHECK any pre-checked toolbar and/or software options presented with the update. They are not part of the software update and are completely optional.

Here is a link that might be useful: javaRA