For most binary file types, Internet Explorer asks whether you want to open or save the file, and gives you a further choice of skipping that prompt in the future. Nothing I do gives me access to this prompt for PDFs and Adobe Reader. On a computer out of the box, with a fresh installed of Adobe Reader set not to open PDFs in a browser window, a click on a link to a PDF will open automatically in Adobe Reader. It will not prompt me whether I want to open or save the file.
I can edit this choice in the registry for any other type of file. For instance, if I set MP3s to open automatically in Windows Media Player when clicked, and then I change my mind, I can delete a certain key in the registry and I'll be prompted once again. This is not true for PDFs associated with Adobe Reader.
So my question is, how can I get Internet Explorer to prompt me whether I want to open or save the PDF?