If you perform a clean boot and determine that a program is causing your modem to dial out at startup, remove the program from the Startup folder or the registry.
For more information about how to troubleshoot this issue, click the following article number to view the article in the Microsoft Knowledge Base:
310560 How to troubleshoot configuration errors by using the System Configuration utility in Windows XP
Disable Automatic Checking
Configure the program that automatically checks for updated components or Web pages so that it does not start when Windows XP starts. To do this, see the documentation that is included with the program or contact the program manufacturer.
Modify the Registry
Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
322756 How to back up and restore the registry in Windows
A registry entry may be set to dial. To resolve this issue, configure Internet Explorer to not connect by using a modem, or set the AutoConnect value in the registry key to 0.
Warning Some programs may configure the registry to dial automatically, and by altering this registry value, you may affect the functionality of these programs.
To configure Internet Explorer to not connect by using a modem, follow these steps:
Start Internet Explorer. On the Tools menu, click Internet Options.
Click the Connections tab, and then click Never dial a connection.
To set the AutoConnect value in the registry key to 0, follow these steps:
Click Start, and then click Run.
In the Open box, type regedit, and then press ENTER.
In the right pane, double-click the AutoConnect value, and then reset the value from 1 to 0.
The autodial feature maps and maintains network addresses to connection destinations. This allows these destinations to be automatically dialed whenever they are referenced. The default Internet connection is automatically dialed unless another Internet connection is configured for autodial.
For more information about the autodial feature in Windows XP, click Start, and then click Help and Support. Type autodial in the Search box, and then press ENTER to view the topics returned.
For additional information about a related autodial issue, click the following article number to view the article in the Microsoft Knowledge Base:
311077 Internet Provider Sign-in Screen Appears with Winsock Program
For additional information about how to troubleshoot startup issues in Windows XP, click the following article numbers to view the articles in the Microsoft Knowledge Base:
316434 HOW TO: Perform Advanced Clean-Boot Troubleshooting in Windows XP
308041 Resources for Troubleshooting Startup Problems in Windows XP