First off, punctuation is your friend. I'm not 100% sure I even understand what you were saying. What I think you're saying is that it runs fine if run by itself in Windows, but not if called from RunOnceEx in the registry. That's consistent with what others are seeing. And those are nearly the same parameters I use for my switchless installer. Unfortunately, I don't know what you can do about it other than contact Sun and see if they know why.