Issue with Java

This is my first time (well technically second but thats a different story) posting on this website. I have an issue on my Dell laptop.

So a while back i broke my hard drive on my laptop and got it replaced. Well now, ever since then, it's been acting weird.

Now though, it's very weird. I recently tried to re-install lime wire and when I attempt to run it, it gives me an error message about something pertaining to Java. Now I've tried reinstalling it and java and such, but to no avail. Now, every time I try to open a video on youtube it crashes fire fox completely.

Do any of you have any idea what my problem may be, or a fix?

I have realized that anything involving Java crashes.

It's a Dell laptop running Windows Vista home edition, but thats about as technical as I can get. I'm beyond tech illiterate, so please dumb it down for me :-D. Thank you.

I'll be on another 20 minutes but I'm definately going to bed after that so if I don't respond I'm sorry, but I will check on this tomorrow morning. Again, thank you all so much.