Error Message "Error 645" Using Dial-Up Networking

When you attempt to establish a connection with Dial-Up Networking (DUN), you may receive the following error message:

This behavior can occur if the Require encrypted password option is enabled on the Server Types tab in the connection's properties, or an incorrect user name or password has been entered.

To resolve this behavior, follow these steps:

1. Verify that your user name and password are correct. If this resolves the issue, skip all the remaining steps. Click Start, point to Programs, point to Accessories, point to Communications,and then click Dial-Up Networking.
2. Right-click the icon for your connection, and then click Properties.
3. For Windows 95, 98 and 98 Second Edition:
   
   Click the Server Types tab, click to clear the Require encrypted password check box, and then click OK.
   
   For Windows Millennium Edition (Me):
   
   Click the Security tab, click to clear the Require encrypted password check box, and then click OK.

You may also receive this error in Windows 95 if TCP/IP is not installed and a dial-up connection is attempted.