Try another method.
Open up My Computer from your desktop.
Next click on TOOLS/Folder Options.
File types tab.
When the list populates, scroll down and find the file extension.
Highlight the extension then look in the section Details for (whatever) extension.
That will show you what program is set to open it.
If you need/want to change it, highlight the extension name, choose CHANGE.
Choose what program you want to associate with that extension, make sure Always use the selected program to open this kind of file is checked,
It may or may not work, since you've done this when the prompt opens.
Edited by Queen-Evie, 14 January 2010 - 06:22 PM.