Traditional dial-up networking is far from dead. There are still many people around who opt to use dial-up networking over newer high speed options. This means there are still those out there struggling to troubleshoot dial-up networking problems and here is a common problem that many encounter.
When establishing a dial-up Internet connection, you may encounter a message telling you that another application or program is using the port. If you receive a message similar to this one, you can try resolving this problem by rebooting your computer or verifying that a connection is not already established, or you can try using a different port. An open program may also be the culprit so in your efforts to troubleshoot the problem close any open programs in case one of them is causing the error to occur.