I had the same problem and uninstalled java and reinstalled it. I also disabled pop up blocker in windows ie7. Then after that I installed limewire and now it works. One other thing - It changed my color scheme temporarily because its not compatible with Vista aero. Very Strange..... and it still won't install frostwire but I'm happy with my outcome thus far. The funny thing is limewire was working fine then all of the sudden a week or two ago it crashed on startup. Hope this helps.

I'm having the same problem, I have a brand new laptop with Windows Vista.
and just randomly Lime Wire doesn't work.
When I click on it, I get the Lime Wire Image where it is supposed to say it's loading.
Yet it doesn't load, then the image goes away and I get the Java/Lime Wire error message.
I've never had this problem before.
but when I try to open Java, I get a black box that has a flashing white line in the top left-hand corner.
can anyone help me?

Uninstalled java and reinstalled it, through add remove programs. Then uninstall Limewire. Reinstall Java directly from the website and then the same with limewire. I had the same exact problem and I'm not sure what caused it but this fixed it.

I had the same problem, complaining about java 5 or later. The thing was I had java 1.4.2 installed next to java 6. When I uninstalled java 1.4.2 from the programs add/remove feature, limewire started working again.

well, that's exactly what happened to me!
I made several attempts, reinstalled java and LW but NO WAY to have LW work!

Only thing I could resolve is that in order to get the java control panel, I have to set javacpl.exe in windows 2000 compatibility mode.

So I finally solved ONE problem ( java virtual machine launcher.... could not find main class. Error message)

But LW is dead

I tried also Limewire beta but still no way to see it work again.
I really have no more ideas....