>It will wrongly return "wwPDF50", because I've Adobe 5.0 installed. However, I don't have PDFWriter 5.0 installed. I don't think UNINSTALL registry entry is relable either.
>

Do you have Distiller 5.0 installed? Did you do partial installation (the case Steve worried me about)? :) Anyway, I've asked the same question at www.west-wind forum, so I hope to receive a 100% reliable solution.