XP, Java 2 I think (whatever version Frostwire installs automatically, Java doesn't show up on the program list and some of the files when I search for Java say 1.5, but another says Java 2).

I've tried it also without any firewall in windows, and I don't use any antivirus software, but the program won't even open.
I also tried the other file sharing program, BearWear and it will open but when I try to search for something, says that there's an error and it can't connect to the gnutella network. It has an automatic page it sent me to that shows the likely causes of the problem but none of them are my problem.
I tried Morpheus and it works good. So I suppose I'll just use that.