When you attempt to open the Phone and Modem Options tool in Control Panel, you receive:

Phone and Modem control panel can not be opened. You may have a problem starting telephony service.

This behavior will occur if the Telephony service is disabled.

To resolve this problem:

1. Open a CMD.EXE window.

2. Type the following command and press Enter:

REG ADD HKLM\SYSTEM\CurrentControlSet\Services\TapiSrv /V Start /T REG_DWORD /F /D 3
3. Shutdown and restart your computer.