This happens because windows has your old password saved into its memory. Follow the steps below to clear old saved passwords.
Windows 7 Instructions
- Open control panel
(Start Menu - Control Panel)
- In the top right of the window make sure to select Small icons for the "View by:" option.
- Locate the setting named "Credential Manager" and open it.
- Under the "Generic Credentials" you should see at least 1 if not more Microsoft Outlook related credentials.
- Once you have located all the Microsoft Outlook credentials, Click the down arrow on the right side to expand the info. Click "Remove from vault" and confirm the deletion by clicking "Yes". Repeat these steps for all Microsoft Outlook credentials.
- Open Outlook and enter current password into box. Make sure to click the "Remember my credentials"
- When Outlook opens confirm you are "Connected to: Microsoft Exchange" in the lower right window.