A good technician always reviews the product documentation before setting up a modem to ensure proper operation and the inclusion of all desired features.
Internal-Modem Expansion Card
As with installing any card or internal board, remember to take the proper precautions against electrostatic discharge (ESD), and, of course, back up your data before you open the computer case. Follow these steps:
Document: Check the current IRQ settings and I/O addresses in the computer. Make a note of available IRQs and addresses.
Configure IRQ and I/O settings for non_Plug and Play compliant systems: Set the modem to an unused COM port and IRQ.
Install the board: Physically install the board in an available expansion-bus slot.
Install any software: Follow the software setup routine and, if needed, fill in the modem settings and any dial-up connections the user requests for Internet access or for logging on to a remote system. To avoid generating any security concerns, do not ask for or accept account passwords. Show the user how to set that part of the connection personally.
For older Windows 3.x or MS-DOS machines and non-Internet connections under Windows 95 and later versions, additional work might be required. Here is a sample of how this part of a typical Windows 3.x SYSTEM.INI file might look:
[386enh] COM3Irq=5 COM3Base=03E8
Set up the command set: Any software that will access the modem must know the correct command set to use for that modem. This means identifying the type of modem so the software will use the correct AT commands. When all else fails, try using a Hayes-compatible modem.
Document your work: Write down all the new settings and changes.
External modems are easier to install than internal modems because they do not run the risk of conflicting COM ports.
Connect to a COM port: Choose either COM1 or COM2. Be sure to confirm that the COM port you are using is assigned to the connector on the computer. If the computer is using a serial mouse, that will be using one of the COM ports, too, and this sets up a potential conflict. You can also use COM3 or COM4 if they are properly installed and configured.
Plug in the cabling: Connect the modem to its power source and to the computer. You will also have to connect a telephone line (RJ-11) from the wall jack to the modem.
Configure software: Configure the software to select the required COM port and the type of modem (command set) used by the specific modem installed.