Your problem description suggests a reqistry problem relating to Adobe Reader. To resolve this problem, you need to correct the file associations beyond what you can see via Open With. To do this:
1.Close the Adobe Reader.
2.Click Start and then click Run.
3.In the Open box, input the full path & filename for Adobe Reader, followed by /unregserver
4.Click Start and then click Run
5.Redo (3), but with /regserver
If you still get no joy, uninstall & reinstall Acrobat Reader to correctly register it in the Windows registry.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]