The important thing concerning dial up is getting the error number. Listed are some of the possible error numbers and possible solutions to them. You might note some of the error codes are different for Windows XP. Also make sure you do NOT have a V92 modem:

DIAL UP:
Error 691: This is usually a username or password error. Ensure that the username and password are in lower case letters. Also make sure you do NOT have the @ponyexpress.net at the end of the username.

Error 650 & 678: You may need to uninstall and reinstall Dial Up Networking in the Add/Remove Programs menu. Before you do this make sure that you have your Windows CD. The following steps will take you through the removal and reinstallation of the Dial Up Networking for Windows 95,98, and ME.

1. Click on Start.
2. Go to Settings.
3. Click on the Control Panel.
4. Double Click on Add/Remove Programs.
5. Click on Windows Setup.
6. Double Click on Communciations.
7. Click inside the box next Dial Up Networking.
8. This should remove the checkmark there.
9. Click OK.
10. Click Apply.
11. If the popup comes to restart the computer, select "NO."
12. Repeat step six and seven above this will reenter the checkmark in the box next to Dial Up Networking.
13. Click OK.
14. Click Apply.
This time when it asks you to restart the computer select "YES."

Error 720: Contact Tech Support.