This document describes a known issue with .AS4 workstation profiles under Windows 64-bit versions.
Resolving the problem
Clients who are accustomed to creating .AS4 workstation profiles on the Windows desktop to start a connection (5250 Display Emulation or System i Navigator) to a specific System i will find that this option is no longer functional in the 64-bit environment.
Additionally, customers who are accustomed to using a pre-configured .AS4 profile to choose which application to open will find that this option is also no longer available in the 64-bit Windows environment.
If a user right-clicks on the .as4 icon as shown:
...the following menu would appear:
allowing the user to choose which application to open.
This is working as designed, and no 64-bit fix is planned at this time.