I'm on Win7x64, and I have Reader 9.3 installed, and I have Windows Live Mail Desktop (2009) installed. I can open an email and save a PDF to the desktop, and then double-click the PDF and it opens in Reader fine. But I cannot double click the attachment and open the PDF. I get an error saying that a default program needs to be associated with the file-type. I checked the default programs, and .pdf is in fact set to open with Reader, as evidenced by the ability to open the file from the desktop.
I've reinstalled Reader several times, and I've tried hints to delete the file-type association and re-create it. Nothing works. I also just upgraded to Reader 9.3, still no change.
The Windows Live Mail Desktop forums suggest that the problem is with Adobe Reader and to contact you. Any thoughts or help?