Certain Java programs and other things stopped working online a long time ago after I ran System Restore when some settings were screwed up, and it got rid of some files or something, I think. I can't access most Java programs, like chat relay and Yahoo Games. Tried resetting all settings, and running Restore from back when it worked. But nothing worked. I mailed Yahoo and told them everything I had tried and they basically told me to try everything I had already tried, it was an automated message.
In addition, after this, I installed a Java runtime pack thing that came with some programs. And Java still doesn't work....

I had a similier when I did a browser enhancement. couldn't get into or see any java.

Here's what you do. Go to Microsoft.com and do to the downloads for Internet explorer, and serach the download "Virtual Machine".

Download that program and run it, It will reinstall the java virtual maching and allowing you to use your java.

Good luck