I have a user who is linking to a PDF file in an Excel document. It is on Windows 7 64bit Enterprise Edition and Excel 2010. All the other links work, but for some reason none of the PDF links do (they all give that error). I have checked, and .pdf is associated with Adobe Reader in Windows. The files open fine if you double click them, but she gets that error when accessing them from a link in her spreadsheet. Does anyone have any ideas?