Linda,
As it happens the instructions were in the latest post on the tech forum. I'm copying that here. I think this will be pretty straighforward but let me know how it goes:

Every now and then a YLD member has trouble getting to chats because their computer is not Java enabled.

All you need to do is follow the instructions on this page:
http://www.java.com/en/download/windows_ie.jsp

This allows you to download and install the FREE - Java Runtime Environment
It's very straightforward.

Hope that helps someone.

Kitty