When you try to open your Public folders or User mailboxes with PFDVAdmin on your Windows 7 client, you receive the following error:
Could not expand http://(your mailbox folders)
In my case, this problem occurs in combination with Exchange 2007.
Resolution
– First, install .NET Framework 1.1. It can be downloaded here. Now retry to open the public folders or user mailboxes.
– If this still is not working, be sure you are using an account which is an Exchange administrator.
– You can also try to open PFDAVAdmin with secondary logon with an Exchange admin account. The steps can be found here:
1. Search for PFDAVAdmin in your Startmenu, Desktop or program location, and right-click on the icon or executable while holding the Shift-key. Now choose Run as another user…
2. Type in the Exchange admin username and password. Also use the same account (Windows logon) to open the public folders or user mailboxes.