You can keep all of the development environments. It's just all the old versions of Java you have. I know sometimes developers use them for testing but they are not secure. If you need to keep them for that then do so, but if not you should remove all the old versions and download/install the newest.
To do that,
Please download JavaRa to your desktop and unzip it to its own folder
Run JavaRa.exe, pick the language of your choice and click Select. Then click Remove Older Versions.
Accept any prompts.
Open JavaRa.exe again and select Search For Updates.
Select Update Using Sun Java's Website then click Search and click on the Open Webpage button. Download and install the latest Java Runtime Environment (JRE) version for your computer.
Also, are you still having the explorer issues?