Microsoft KB Archive/152988

= Works: Troubleshooting Communications Problems in Windows 95 =

Article ID: 152988

Article Last Modified on 11/15/2006

-

APPLIES TO


 * Microsoft Windows 95
 * Microsoft Works 2.0 Standard Edition
 * Microsoft Works 2.0a
 * Microsoft Works 3.0 Standard Edition
 * Microsoft Works 3.0a
 * Microsoft Works 3.0b
 * Microsoft Works 4.5 Standard Edition
 * Microsoft Works 4.5a
 * Microsoft Works 4.0 Standard Edition
 * Microsoft Works 4.0a

-



This article was previously published under Q152988



SYMPTOMS
When you attempt to communicate with an internal modem using the same COM port as an existing on-board COM port, multi-I/O board or other device (such as a mouse or scanner), you may experience various problems, depending on the hardware and BIOS used. These problems may occur even if nothing is connected to the physical COM port.

Symptoms may include the following:


 * The system stops responding (hangs) when you create a communications document, try to connect, or use Dial This Number.


 * The system reboots when attempting to dial or connect.


 * The modem dials and rings but does not connect.


 * The modem dials but the message, NO CARRIER, is displayed.


 * You receive an error stating that the Modem is Busy or Not Responding.


 * The mouse cursor disappears.



RESOLUTION
If your modem is not configured correctly, Work's Communications module may not function properly. The following procedures list steps to verify the correct operation of your modem and communications in Windows 95.

After finishing each section, try to use the modem. If you still experience any of the symptoms listed above, proceed to the next section.

Check Modem Settings and That Windows 95 Can Communicate With the Modem

 * 1) Click Start, point to Settings, and click Control Panel.
 * 2) Double-click Modems.
 * 3) Verify that your modem manufacturer and model is listed correctly. If it is not listed, click Add to run the Install New Modem Wizard which will detect the modem and confirm it with the current Registry configuration.

NOTE: If the manufacturer and model are not correct or not available in the list, choose one of the Standard types of modems with a baud rate that matches your modem.
 * 1) On the General tab of the Modem Properties dialog box, select your modem and click Properties.
 * 2) Verify that the port is set to the port your modem is on. If not, select the correct port and then click OK.
 * 3) On the Diagnostics tab of the Modem Properties dialog box, select your modem and click More Info.

Windows will attempt to communicate with the modem. If this is unsuccessful, or you receive an error message, Windows is having difficulty communicating with the modem.

Check for Device Conflicts
Determine if the communications port I/O addresses and IRQ settings are properly defined and there are no conflicting devices.

 In the Control Panel, double-click System. On the Device Manager tab, click the plus sign (+) next to Ports. Choose a port and click Properties. On the General tab, verify that Device Status lists the device as working properly. Click the Resources tab to display the current resource settings for the port. Consult your modem manual or contact the modem manufacturer to establish the correct settings. Verify the Conflicting Device list shows NO conflicts. If the modem is in conflict with another device, do the following:

 Clear the check from the Use Automatic Settings box.</li> Click the menu in Setting Based On and choose a configuration that does not have resource conflicts.</li> Click Change.</li></ol>

NOTE: Do not use a modem on COM3 if you have a serial mouse or other device on COM1. Usually COM1 and COM3 use the same interrupt request line (IRQ) and cannot be used simultaneously; COM2 and COM4 also typically use the same IRQ. If possible, change the COM3 and COM4 port to an IRQ setting that is not in conflict.

Some display adapters have an address conflict with the COM4 port. To work around this conflict, use another COM port or replace your graphics adapter.</li> Make sure you check all the devices listed under Ports, repeating steps 4-7 above.</li></ol>

Verify the Port Settings and the Modem Is Enabled
<ol> In Device Manager, click the plus sign (+) next to Modem.</li> Select your modem, and then click Properties.</li> On the General tab, verify the following:

The Device Status lists the device as working properly.

</li> On the Modem tab, verify the following:

The baud rate is set to the speed of your modem.

</li> Click the Connection tab and verify the following:

The data, parity, and stop bits, are correct for the connection you are trying to establish.

The Wait For Dial Tone Before Dialing box is checked.

</li> Click Port Settings and verify the UART type.</li></ol>

Data transmission problems may occur when a baud rate greater than 9600 is selected on a slower computer not equipped with a 16550 UART, or when performing other tasks during a download. If problems or errors occur during transmission, try lowering the baud rate. Attempting to use baud rates greater than 9600 on computers equipped with 8250 or 16450 UARTs will result in dropped characters.

Reduce the Baud Rate

 * 1) Follow steps 1-2 in the "Verify the Port Settings" and the "Modem Is Enabled" section above.
 * 2) On the Modem tab, reduce the baud rate and check the Only Connect At This Speed box if it not already selected.

NOTE: Lowering the baud rate is recommended when using an older computer. If the system you are calling cannot communicate at the initial baud rate, it may be able to communicate at a slower baud rate.

Check Communication Files
Some communication programs designed for Windows 3.1x install incompatible driver files which may cause COM ports and modems to stop working. Verify the required communication files are present and they are the correct sizes and dates for Windows 95.

To Verify the required communication files do the following

<ol> Click Start, point to Programs, and then click Windows Explorer.</li> Click the plus sign (+) to the left of the Windows folder.</li> Click the System folder.</li>  In the right pane, verify the following information for these files: <pre class="fixed_text">     Comm.drv            5,856 bytes          7/11/95 Serial.vxd        18,572 bytes          7/11/95 </li> If these files are not found or are not the correct size or date, expand new copies of them from the Windows 95 CD-ROM or floppy disks. For information on how to do this, see your Windows documentation or on-line help.</li></ol>

Verify Settings in the System.ini
<ol> Click Start, and then click Run.</li> <li>Type System.ini, and then click OK.</li> <li> Verify the following lines: <pre class="fixed_text">    [boot] comm.drv=comm.drv

[386enh] device=*vcd </li></ol>

Check for Incorrect Jumper Settings or Faulty Hardware
If none of the steps above resolve the conflict, you may have a hardware problem, such as jumpers on your motherboard or modem may be set incorrectly. Consult your modem manual or contact the manufacturer of your modem for additional hardware diagnostic tests.

<div class="moreinformation_section">

MORE INFORMATION
Many PC motherboards ship with two built-in COM ports. Even though there may not be an external connector for the second COM port, the COM port circuitry is on the motherboard and must be disabled to reliably use an internal modem on COM2. Reconfiguring the COM ports usually involves changing a DIP switch or moving a jumper. Consult your hardware documentation for more information about configuring the COM ports.

Additional query words: 2.00 2.00a 3.00 3.00a 3.00b 4.00 4.00a 4.50 4.50a w_works hang t-shoot tshoot com1 com2 com3 com4 switch switches win_95 hyperterminal wcm again i/o locks up freezes freeze crash

Keywords: kbenv kbinfo kbtshoot KB152988

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.