The server application, source file, or item can't be found, or returned an unknown error. You may need to reinstall the server application. can open pdf file embedded in office files.__

Steve, Many thanks for such a good reply. I am using Acrobat Reader 10.0.1 and I too have the problem with server application unknown error. I uninstalled and reinstalled Acrobat Reader but still get the same effect. When I look at the .pptx in .zip format, the embedded .pdf files are shown as .bin extensions even though they show up in PowerPoint as Acrobat Document Objects. When I use Notepad to look at the .bin files, I can see that the %PDF header is about 2560 bytes into the file. If I cut out the 2560 bytes using notepad, Reader complains about the resulting file and indicates a corruption in the file. Embedded .xlsx and .doc files work fine even though they too have an approximate 2560 byte preamble. Do you have any other hints about how I might be able to resurrect the embedded files? Is there a tool which can extract the embedded files without the embedding info? Thanks.

(10 Minutes Later . . .) Found that the reason is because Adobe Reader X has a new Protected mode. See http://acrobatusers.com/forum/general-acrobat-topics/cant-embed-pdfs-excel-reader-x#comment-76344 . When I turned this off, Reader was able to handle the embedded files passed to it by Powerpoint.

You could always install Acrobat Reader (then later reset your file associations so that your preferred PDF program is the one that gets launched when you doubleclick a PDF).

But first, try this:  rightclick the embedded PDF, click Adobe Document Object and see if there's a Save option that'd let you save the PDF out to your hard drive. 

If not, see what Open does. 

Or try saving as PPTX (if it's not in that format already), then add a .ZIP extension to the end of the PPTX filename and open it as a zip file.  Poke around the various folders inside the zip ... you *might* just find the PDF available there.