I am running Excel 2007 in Windows 7. Ever since Reader X (ver 10.0) was installed, I haven't been able to attach PDFs to Excel documents, nor can I open any previously embedded PDFs in existing Excel documents. To embed a new PDF, I am using "Insert-Object-Create From File" then when I select a PDF document, it comes back with an error message saying, "Cannot insert object". When I try opening a previously embedded PDF in an existing Excel file, I get an error message that says, "Cannot start the source application for this object". I am not having trouble embedding or opening other file types - this has only affected PDFs.