A modem is a device that translates data between the digital signals used in computers and the analog signals that can be transferred across phone lines.
Most PCs today that are not designed to be connected to a network come with a modem, because in addition to allowing the user to access on-line services and bulletin boards, send faxes, and place phone calls, modems provide access to the Internet and e-mail, which are increasingly important to more and more people.
If you already have a modem but want better performance, it is usually advisable to upgrade to a faster model.
However, the present modem technology has some limitations that make the price of a new modem in some cases not worth the increase in speed.
The fastest modems today can receive data from across the Internet at about 56 kilobits per second, or kbps, only under ideal situations;
that is, there must be high-quality phone lines linking the modem to the Internet service provider, and the Internet service provider must also use modems with the same technology.
Moreover, they can function only half as fast when sending data across the Internet and when sending or receiving data without using the Internet service provider.
For example, information can be sent to or retrieved from bulletin boards at 33.6 kbps at most, because the Internet service provider is not involved in this connection.
The previous generation of modems, on the other hand, which can send and receive data at speeds of at most 33.6 kbps, use older, more supported technology and thus can achieve peak performance under a greater range of conditions.
They require neither phone lines of particularly high quality nor an Internet Service Provider with a special kind of modem.
A full hardware upgrade from a 33.6 kbps modem to a 56kbps modem, therefore, may not be very economical.
Modems are sold as either internal or external.
Internal modems are mounted inside the computer in one of the computer's ISA or PCI expansion slots, while external modems reside outside of the computer's case and are connected via the serial port.
There is no difference in performance between the two types, but internal modems tend to be less expensive.
Internal modems range in price from $50 to $275.
Speed should be your biggest consideration when you're purchasing.
If you are purchasing a 56 kbps modem, this includes making sure that it will be compatible with your Internet service provider.
You may be able to narrow your choices by considering special features such as Call Waiting, distinctive rings for different types of calls, and teleconferencing or fax software that many modems come equipped with.
The warranty on the modem may also be an important factor, because modems are vulnerable to damage in power surges.
Before buying an internal modem, make sure that you will have a free ISA or PCI slot.
Also, if space inside your computer is limited, shut down and open up your computer and measure the space around the free slot; some modems may be too large.
A Phillips screwdriver and about 45 minutes of time are required to install an internal modem.
Click here for a list of links to internal modem manufacturers.
- If you are replacing an older modem with a newer model, click on the Start button, move the cursor to Settings, and click on Control Panel.
Double click on the Modems icon.
Click on the General tab, and then select your older modem.
Click Remove, and then click OK.
- Make sure the computer is turned off.
- Carefully disconnect the cables from the back of the computer, place the computer on a stable working platform, and remove the outer case. Discharge any static electricity in your body by touching the computer's power supply.
- If you are replacing your internal modem:
Locate the ISA or PCI slot holding the older modem. Remove the screw holding the modem
in place, and put the screw in a place where it will not get lost. Carefully pull the modem directly out
of its slot, with as little lateral motion as possible.
Look on the older modem for two sets of eight or ten small, straight metal pins, with a small plastic cube possibly connecting two pins of each set.
These are the modem's COM port and IRQ settings. If each of the two plastic
cubes (called "shunts") is dangling from only one jumper pin instead of connecting
two, then the older modem was configured for Plug-and-Play. If each of the two
shunts is connecting two pins, then the older modem was configured for specific
COM port and IRQ settings. If this is the case, then you should write down these
settings (the pins should be labeled). In either case, it is recommended that
the COM port and IRQ settings of the new modem be configured in the same way
as those of the old modem, even if the installation manual of the new modem
says to use only the Plug-and-Play settings. Matching the settings will reduce the
probability of a hardware conflict to the greatest extent.
- If you are adding a modem:
Locate a free slot of the type appropriate for your new modem (either ISA or PCI).
Unscrew the expansion slot cover (a metal strip blocking the opening next to the expansion slot) and remove it.
Put the screw in a place where it will not get lost.
- Remove your new modem from its anti-static bag. If you are upgrading your modem, match
the COM port and IRQ jumper settings with those of the older modem (see step 4 above).
If you are simply adding a modem to your computer, set the jumpers as the manufacturer
recommends. Line up the edge of the
modem containing the metal contacts with the ISA or PCI slot and push the card in firmly with its metal plate facing the back of the
computer. If you find it too difficult to push the card in directly, insert one corner of the card into the expansion slot,
then push the rest of the card into place. Secure the card with the previously removed screw.
- Replace the computer's outer case, and carefully move it back to its original position. In
addition to replacing all of the original cables, connect a telephone wire between a
wall jack and the port labeled "wall" (or something similar, but not "phone") on the
- Start up the computer.
Windows should recognize the new modem and attempt to install the drivers for it.
It may prompt you to insert the Windows 9x CD or the CD or floppy disk that came with the modem.
- Click on the Start button, move the cursor to Settings, and click on Control Panel.
Double click on the System icon. Click on the Device Manager tab, then expand the
the Modem category. There should now be an entry for your newly installed modem.
If there is no entry, or if the entry has a yellow circle with an exclamation mark next to it, your modem is not configured properly or there is a hardware conflict of some sort.
Most likely, any conflicts will regard the modem's COM port or IRQ settings.
Consult the manual that came with your modem and/or use the Windows Troubleshooting Guide to resolve the problem.
To access the Troubleshooting Guide, click on the Start button, then click on Help.
Troubleshooting should be listed in the table of contents.
- Install any software that came bundled with the modem.
- The next time you use Dial-Up Networking, you will have to briefly configure it to use
your new modem.
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