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SYMPTOMS
When you start Microsoft Office Outlook 2003 or Microsoft Outlook 2002 Service Pack 3 (SP3) after you upgrade from an earlier version of Outlook, you are prompted to enter your user name and password. The user name and domain name that you used when you previously logged on to Microsoft Exchange Server are not displayed in the dialog box that appears on the screen.
CAUSE
This behavior may occur if the Interactive Logon: Do not display last user name local security policy setting is enabled on the computer. When this local security policy setting is enabled, the user name and the password of the last user who logged on to the computer is not displayed in the Log On to Windows dialog box.
If the Interactive Logon: Do not display last user name local security policy setting is turned off, the user name and domain name information that you use to log on to Microsoft Exchange Server is stored in the LogonDomain entry and in the UserName entry in the following registry key:
HKEY_CURRENT_USER\Software\Microsoft\Exchange
If the Interactive Logon: Do not display last user name local security setting is enabled, your user name and domain information is not stored in the Windows registry and user name and domain name that you used when you previously logged on to Microsoft Exchange Server are not displayed in the dialog box that appears on your screen.
WORKAROUND
To work around this behavior, turn off the Interactive Logon: Do not display last user name local security policy setting.
To do so: Open the appropriate Group Policy object, expand Computer Configuration, expand Windows Settings, and then expand Security Settings.
Expand Local Policies, and then click Security Options.
In the right pane, double-click Interactive Logon: Do not display last user name.
Click Disabled, and then click OK.
joegz
"Sometimes you just need to find out what it's not first to figure out what it is."