If I'm understanding your situation correctly I believe the following will help. Open My Computer (or just Windows Explorer), right-click on the DVD player's drive letter, choose Properties, select the AutoPlay tab. Now use the drop-down to choose Video file. The installation process for PowerDVD (or any other DVD player) should have caused the software to show up in the Actions box. You should just click on the "Select an action to perform:" radio button and choose the PowerDVD from the list. Click on OK. Or you can have the AutoPlay function ask you which app to play video files with each time by using the "Prompt me each time to choose an action" radio button.
- Collin