This could be an answer to what DtLr2610 and possibly the mexican were describing.
Today, after having successfully used iriverter at home, I attempted to install it on my work pc, which runs XP as well. Before I installed it, I remembered I needed java so I went to
www.java.com and downloaded something without really thinking about it and installed it and ran iriverter and it worked. However, I tried to run it again later and it had stopped working. I would click on it and I'd get an hourglass and then nothing would happen.
I backsearched this thread a bit and realized that I needed to download java at this location (
http://java.sun.com/j2se/1.4.2/download.html). After downloading and installing that version and uninstalling whatever other java thing I had downloaded, it worked fine.
So my recommendation to people who are having trouble with the program not doing anything when you click on it, is to make sure you have this correct version of java.