If you visit http://www.privacy.net then click on "Analyze Your Connection" this should list all the different stuff that works like java-script, java, activex, etc...

Then this site can help you with java http://www.virtualmachine.tk/

Now, I know that a lot of different programs can make java-script not work. Programs that cause problems:

Norton Anti-Virus (But only if you let the Firewall part of this install)
Any Pop-up killer
Lots of Tool Bar add-on's