Dieser Artikel sollte Ihr Problem beheben: http://support.microsoft.com/kb/956531
Laden Sie den Hotfix herunter. Gehen Sie folgendermaßen vor, um den Hotfix zu aktivieren:
> 1. Exit Outlook 2007. > 2. Start Registry Editor. > * In Windows Vista, click Start > Collapse this imageExpand this image > the Start button >, type regedit in the Start Search box, and then press > ENTER. > > Collapse this imageExpand this image > User Account Control permission > If you are prompted for an administrator password or for > confirmation, type the password or > provide confirmation. > * In Windows XP, click Start, click Run, type regedit in the > Open box, and then click OK. > 3. Locate and then click to select the following registry key: > HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\RPC > Note If the RPC key does not exist, follow these steps: > 1. Right-click the Outlook key, point to New, and then click Key. > 2. Type RPC, and then press ENTER. > 4. After you select the key that is specified in step 3, point to New on > the Edit menu, and then click DWORD > Value. > 5. Type UseWindowsUserCredentials, and then press ENTER. > 6. Right-click UseWindowsUserCredentials, and then > click Modify. > 7. In the Value data box, type the value that you want to use, and then > click OK. > > Note When you set the UseWindowsUserCredentials value to 1, > only the user's desktop credentials > will be used. The following scenarios > may help you determine the value that > you want to use. > * Account: Domain > UseWindowsUserCredentials: 0 (or not present) > Protocol: TCP, HTTP with NTML authorization > Result: Connect to Microsoft Exchange without prompting > for user credentials. > * Account: Non Domain > UseWindowsUserCredentials: 0 (or not present) > Protocol: TCP, HTTP with NTLM authorization > Result: Prompt for user credentials and connect to Microsoft > Exchange. > * Account: Domain > UseWindowsUserCredentials: 1 > Protocol: TCP, HTTP with NTLM authorization > Result: Connect to Microsoft Exchange without prompting > for user credentials. > * Account: Non Domain > UseWindowsUserCredentials: 1 > Protocol: TCP, HTTP with NTLM authorization > Result: Does not prompt for user credentials, and will not > connect to Microsoft Exchange. Remains > in the disconnected state, > occasionally trying to connect. > * Account: Domain > UseWindowsUserCredentials: 1 > Protocol: HTTP with Basic authorization > Result: Prompts for user credentials and successfully connects > to Microsoft Exchange. Additionally, > it will continue to prompt you if you > mistype your password. > * Account: Non Domain > UseWindowsUserCredentials: 1 > Protocol: HTTP with Basic authorization > Result: Prompts for user credentials and successfully connects > to Microsoft Exchange. Additionally, > if you mistype your password, it will > continue to prompt you. > * Account: Domain > UseWindowsUserCredentials: 1 > Additional Steps: When you configure the profile, select Always > prompt for username and password. > Result: Prompts for user credentials and successfully connects > to Microsoft Exchange. > 8. On the File menu, click Exit to exit Registry Editor.