At work we have Outlook 2010 32-bit, currently version 14.0.7194.5000, with Exchange server.
When I received encrypted mails, I used Thunderbird instead, because it simply didn't work back at Gpg4win 2.x. Nevertheless those mails are still stored in some folder in Outlook and have been "touched" by the old GpgOL. I don't know, if untouched mails would also be a problem.
While current mail flow works well, GpgOL crashes when trying to view those old mails.
My PC is running Windows 7 x64.