How to fix a java registry key error?

I'm sort of a computer novice, but I know very well what I'm doing. I can't install java because of a registry key error, and third party software isn't working. I took it to Geek Squad, but they said it would be way too expensive to fix. What do I do? I JUST WANNA PLAY MINECRAFT!

Get a program called CCleaner. It is free, and it comes with a total uninstaller / registry tool. I would first uninstall every version you have through the uninstaller found in CCLeaner under TOOLS

Then, run the reg cleaner, then restart. Make sure you are running the correct version of JRE as well. Sometimes, if you step back to Java Runtime Environment 6 it helps.

If you're running XP, visit http://www.oracle.com/...80261.html

For Vista and later versions, visit http://www.oracle.com/...33155.html

Accept the license terms, then download the Windows x86 Offline version.

When the download completes, right-click the program and click Run As Administrator, then respond as need to the Or, for Windows XP, log on to an account with administtator's rights and double-click the program.