[solved] Java is broken on my machine - What do?

I turned on my computer today, and noticed that Java was acting quite strange.

Firstly, I can still run applets in the browser, and the Java path (via Control Panel) is normal.

However, when I try to run jar files, Java will not turn on. Also, when I try to start Eclipse, I get this error message:

Should I uninstall Java and try again? I don’t want to break anything…