"Error 633 - the modem (or other connecting device) is already in use" error message when you try to establish a VPN connection in Windows Server 2003
- Explicitly reserve the TCP port that is used for the VPN connection. To do this, follow these steps:
- Click Start, click Run, type regedit.exe in the Open box, and then click OK.
- In Registry Editor, locate and then click the following registry subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
- On the Edit menu, point to New, and then click Multi-String Value.
- Rename the multi-string value as "ReservedPorts," and then double-click ReservedPorts.
- In the Value data box, type 1723-1723, and then click OK.
- Quit Registry Editor.
- Use the netstat command to find the program that uses port 1723. Then, end the process for that program. To do this, follow these steps:
- Click Start, click Run, type cmd.exe in the Open box, and then click OK.
- At the command prompt, type the following command, and then press ENTER: netstat -aon
- In the output that is displayed, identify the process ID for the program, if any, that uses TCP port 1723.
- At the command prompt, type the following command, and then press ENTER: taskkill /PID PID /FNote The taskkill command ends the process that corresponds to the process ID number. The /F option is used to forcefully end the process.
- At the command prompt, type exit, and then press ENTER to quit the command prompt.
- Restart your computer. This may cause the program that uses TCP port 1723 to use a different port.
Article ID: 885959 - Last Review: 10/30/2006 21:32:35 - Revision: 1.2
- kbtshoot KB885959