Acrobat not opening .pdf files correctly

[MSR63]

I have a user that has the standard Adobe Acrobat ver 6 program (same as all inhouse - users)

The program itself will open .pdf files (file, open, open from file located on desktop and/or shared drive etc..)
However, when you attempt to open an attached .pdf in Outlook 2000 or even a .pdf file copied on the desktop

Troubleshooting steps alread taken.
* uninstall Adobe Acrobat, reboot and reinstall (both under user and administrator profile)
* Delete user profile

Every thing I've tried seems to fail - last resort, remove PC and issue user new one, reload old.

Is there anything else that someone might be able to think of that would help?

Thanks