Symptom
No dial tone error message when trying to dial out with modem. The message indicates that the modem was unable to detect a clear and distant dial tone on the telephone line.

Affected configurations
Any ThinkPad system with built-in modem

Solution
This problem can be due to the software not handling a certain dial tone rather than a specific hardware fault. Around the world there is a variance in the signal quality of the dial tone which causes a report of no dial tone detection. Disable the dial tone detection to prevent the system from trying to detect a dial tone.
Disabling dial tone detection for modems:
Windows XP/Windows 7

1. Click Start
2. Select Control Panel
3. Click Switch to Classic View to change the control panel view
4. Click Phone and Modem Options (At this point, you may be prompted to enter your area code, then click OK or Next)
5. Select the Modems Tab
6. Select the installed modem (For example: ThinkPad Modem Adapter)
7. Click the Properties button
8. Select the Modem tab in the Properties window
9. Click Wait for dial tone before dialing to remove the check from the checkbox.See Screenshot, below:
   
10. Select the Advanced tab
11. Add "X3", without quotes, to the Extra initialization commands field in the Extra Settings box
12. Click OK twice
13. Close Control Panel

Additional information
Click here for more information about troubleshooting and diagnosing modem issues