Ways to solve fax machine failure in Vista

When trying to send or receive a fax using Windows Fax and Scan in Windows Vista, the transfer process may not complete after the connection is established.
Fault Cause
This issue may occur if one of the following conditions is true: • There is line noise on the telephone line connected to the modem.
The modem has an abnormal behavior.
A timing issue has occurred between the computer and the modem.
Warning: Serious problems can occur if you modify the registry incorrectly by using Registry Editor or by other means. These issues may require reinstallation of the operating system to resolve. Microsoft cannot guarantee that these issues will be resolved. Modifying the registry is at your own risk.
Workaround
In order to resolve this issue, you must use different class support to retransmit the fax. To do this, follow these steps:
1. Click “Start”, type device manager in the "Start Search" box, and then click “Device in the “Programs" Manager”.
2. Expand “Modem", right-click the modem you are using, and then click “Properties”. //This article is transferred from www.45it.com Computer Software and Hardware Application Network
3. On the “Diagnostics” tab, click “Query Modem”.
4. In the “Command” column, find “AT+FCLASS=?”, then write down the value in the "Response" column.
Note: If the value contained in the "Response" column is “1”,“2” or “2.0”, then the modem supports Class 1, Class 2, and Class 2.0, respectively.
5. Click “Start”, type regedit in the "Start Search" box, and then click “regedit” in the “Programs"
6. Locate and then click the following registry subkey:
HKEY_LOCAL_MACHINE\\Software\\Microsoft\\Fax\\TAPIDevices
7. Expand “TAPIDevices”, and then click the device ID of the modem.
8. Click “Modem”, right-click “FixModemClass”, then click “Modify”.
9. In the "Value data" box, type one of the following values ​​depending on the class you want to set:? Typing 1 sets the fax modem to use class 1
Typing 2 sets the fax modem to use Class 2
Typing 20 sets the fax modem to use class 2.0
10. Exit the Registry Editor.
11. Restart the fax service. To do so, click “Start”, type the service in the "Start Search" box, and then click “Services> in the “Programs"
If you are prompted for an administrator password or for confirmation, type your password or click “Continue”.
12. In the "Services" list, click “Fax”, then click “Restart”.
13. Try to send a fax. If this problem occurs again, repeat steps 1 through 12 and set the modem to use a different class.