Windows 7: Phone and modem country list empty

I am using "dell latitude e6520" with Windows 7 professional 32 bit operating system.



Control Panel->Phone and modem/ country list is always empty.
I checked registry and found that "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Telephony" is not having "Country List". I found "Country List" in an other laptop(Windows 7 professional 32 bit OS). It was copied and imported to my machine.

Now, when I try to open Phone and modem, it is showing location information with a valid country list. But, I am not able to save the details.

Every time on clicking Phone and modem, system is asking for location information.

Also, I found/changed the following :
1. I changed the value of "CountryListVersion"(HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Telephony\Coun try List) to 0.
2. Though startup type of "TapiSrv" (Telephony) is set as Automatic, it is not starting automatically. I manually started the service and after sometime(not sure when) it automatically stopped.

I tried sfc/scannow also. But, Windows Resource Protection did not find any integrity violations.

Thanks in advance for your help