Java problems

Hello,

I have Windows Vista on my pc and it was working fine as far as looking at youtube videos or playing games on aol. Now, I can't watch youtube videos or play games on aol. Every itme I try to I get a message that java is not enabled. I went into the internet settings like it says and according to that my java is enabled, but it still doesn't work. What should I do?<code>Configuration: Windows Vista
I have internet explorer. I can't download firefox either.