Hold your taught that Adobe is incompatible with Microsoft especially x64 bit! a simple registry change may save the day..
let's say we have a KAMPRET.pdf file, and it cannot be open using pdf preview handler as shown on the figure below:
go to 'regedit', and browse for below folder:
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Classes\
CLSID\{DC6EFB56-9CFA-464D-8880-44885D7DC193}
change the value of 'AppID' with below set of numbers:
{534A1E02-D58F-44f0-B58B-36CBED287C7C}
close the registry, restart your MS Outlook, and whoala.. ;)
