Outlook 2007 on Vista using RPC over HTTP "OutlookAnywhere"

by Christopher Kusek (PKGuild) Exchange, Informational, Microsoft

Disclaimer: The following solution does work and has worked for me. And until further notice (I find an alternate solution to this, will be my solution for now)

I ran into a bit of an awkward situation. RPC over HTTP was not working on my Vista Ultimate box when I started using Outlook 2007. I discussed with other people and they were all fine, however they were using Outlook 2003, so not clearly the indicator I was hoping for.

Having some others test with their Outlook 2007 clients, I ran into further failure to communicate, resolving in the need to find a solution!

I did find just one solution (which does work, until further notice).

This solution resides in the following registry key

HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\RPC

With the creation of the key DefConnectOpts (set to DWORD = 0).

The DefConnectOpts registry value helps to turn down some connection optimizations added in Outlook 2007.

So not exactly what I’d prefer, but it is something which will work when you do want your RPC over HTTP Functionality to work for you.

Some awkward things regarding this is, I did not even have the RPC key present in the registry, which prompted for the creation of that key so I could set that DWORD value. So for now, anyone having similar problems with Vista/OL2007 or somesuch and are looking for some resolution, I did find success here. I’ll continue to find a “better” solution which doesn’t involve client-hacking to go about fixing it.

1. Click Start, click Run, type regedit in the Open box, and then click OK.
2. Locate and then click the following subkey:
HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\RPC
3. On the Edit menu, point to New, and then click DWORD Value.
4. Type DefConnectOpts, and then press ENTER.
5. Right-click DefConnectOpts, and then click Modify.
6. In the Value data box, type 0, and then click OK.
7. Exit Registry Editor.
8. Check the effect by using the NetBios name.

Error messages when you try to connect Outlook 2007 to Exchange Server: “The action cannot be completed. The connection to the Microsoft Exchange Server is unavailable” or “Your Microsoft Exchange Server is unavailable”
http://support.microsoft.com/?id=913843

Some additional notes which may help resolve this problem:

Adding another dword value of EnableRPCtunnel with a value 1.

Christopher Kusek