If the PDF is on the same machine that is running IIS, then you can try giving "everyone" read access to both the file and the directory in which it resides. If your virtual directory mappings and HREF syntax are correct, this should work. At least it's a starting point to confirm, "yes IIS is working OK and there's a security problem somewhere".
If the PDF is on another machine, it's a bit trickier (has to do with using UNC syntax and configuring IIS with a virtual folder that maps to the UNC destination).
>I followed the instructions, restarted IIS and am still getting the 404 error. Any other ideas?
>
>>Is the file a defined MIME type in IIS6? If not, IIS6 won't serve it up, while IIS5 did with no questions.
>>See:
http://support.microsoft.com/default.aspx?scid=kb;en-us;326965>>
>>>>From Windows Explorer should work.
>>>
>>>I think we are miscommunicating. I can access the file from Windows Explorer, but I want IIS to serve up the file since this is part of a web application.