Java applets closing my browser

[DC]

Whenever I try to run a java applet in Firefox, it automatically closes Firefox.  Same with IE (though in IE's case, it simply closes and reopens the tab (blank) saying there was a problem that caused that; no details though).  I reinstalled java, ran virus scanner, etc.  Anyone know what's going on?  Google results mostly say something related to add-ons (but IE has the same problem) or AVG anti-virus (I don't use that).  I feel like something critical may have been deleted at some point.

[Grakelin]

Have you tried reinstalling Java?

Source: Not an expert, ask Blake.

[DC]

Yeah, I mentioned so in the post.

[BlakeJustBlake]

Source: Not an expert, ask Blake.

Don't ask me shit, I don't know anything. I would just say something like your shit can't handle it.

Source: Not an expert, ask Jane.

[DC]

A couple months ago this virus began systematically deleting files on my hard disk, so I had to restore to a previous system point and reinstall a few programs.  But there are still a few unsolved consequences of that event such as this.  Java seems to be missing something that is assumed to be on the computer; if it was in the download package there wouldn't be an issue.