I have the same issue. In my case, the decoder was working just fine, up until I did a repair option on my windows. All the updates finished, and all is great, except that when I tried playing a DVD, I got a message that there was no decoder. I tried reinstalling it, to be told it was already installed. Same issues with it not being listed anywhere, too. Then, I decided to check the registry, clear out any old entries, and do a clean install. After that, I got that same message - This program does not support the operating system detected - even though it was working just great on this OS before. Did you ever get a solution? Really hope there is one, as I don't want to have to pay for yet another decoder (from someone else).