System Hangs in Communications, Dial This Number, or Tools (111345)

SYMPTOMS

Interrupt (IRQ) conflicts or third-party communications drivers can cause your system to stop responding (hang) or cause other problems in the areas listed below.

When you create a new Communications document or access the Modem Setup dialog box (available from the Settings menu) or the Options dialog box (available from the Tools menu), the following problems may occur:

The mouse pointer may freeze momentarily or until you restart your machine.
A Windows blue screen may be displayed with the following error message:
The requested COM port is not available because a hardware interrupt conflict has been detected. You must change your hardware configuration to be able to use this COM port from within Windows applications.
The machine may exit to an MS-DOS prompt or to a flashing cursor.

When you use the Communications module, the following behavior may occur:

When you attempt to dial, the modem may not initialize, and the dialing status may count down from only five seconds.
The Modem test may report "No modem found" and/or the mouse may hang.

NOTE: If the mouse hangs when you run the modem test, note which COM port is being checked at the time, indicated in the status field. Be careful because an interrupt conflict can cause the system to stop when you are running the modem test.
Random or missing characters or incorrect line spacing may be displayed if you are connected to another workstation or a bulletin board service (BBS).

When you use the Dial This Number command, the following behavior may occur:

The modem may not dial the number.
It may dial the number, but not release the line. You may be able to hear the other person over the modem's speaker but won't be able to talk over the phone.
The mouse may hang after you choose Dial This Number. "Working..." will be displayed on the status bar.

RESOLUTION

To correct the problem, check the following:

Make sure there are no other hardware devices using the same interrupt as the modem:
```
      COM1 and COM3: IRQ4
      COM2 and COM4: IRQ3
						
```
If there is another device, such as a mouse, trackball, digitizer tablet, scanner, fax card, net card, or sound card using the same interrupt, either change the interrupt of the modem or the other device, or remove the other device from the system.

For information about how to change the interrupt of the modem or other device, see the documentation for the device or contact the manufacturer. The method used to change the interrupt depends on the device because it may be a jumper, a DIP switch setting, or software.
Check the COMM.DRV= line in the [boot] section of the SYSTEM.INI file. If it indicates a third-party communications driver, comment out the line by placing a semicolon in front of it, and then add the following line to the [boot] section:
```
      COMM.DRV=COMM.DRV
					
```
If the port is using a UART 16550 chip, add the following line to the [386Enh] section of the SYSTEM.INI file:
```
      COMxFIFO=1
					
```
Pentium machines with Windows for Workgroups require an updated SERIAL.386 file.

For additional information about the Communications module hanging Windows for Workgroups when you are using a pentium machine, please see the following article in the Microsoft Knowledge Base:
114015 Works Communications Hang Using WFW 3.11 on Pentium Machine
Notebook/Laptop PCs that power down serial ports to save power must disable this feature. The power down serial port automatically turns off the power to the serial port.

MORE INFORMATION

To determine that the problem is due to an interrupt conflict on the same port as the modem, try the Autodial feature in Windows Cardfile or try dialing from Windows Terminal, as listed below.

NOTE: If the conflict is on an interrupt other than the one to which the modem is set, Cardfile and Terminal may still work even though Works does not.

Cardfile

From the Windows Accessory group, open Cardfile.
Enter a phone number in any card.
From the Card menu, choose Autodial.
Choose the Setup button, confirm that all settings are correct, and choose OK.

If there is a conflict on the same IRQ as the modem, the following message will be displayed:

Cannot dial modem. Check Control Panel to see that the modem is installed properly, and check the modem cables to see that they are connected properly.

Terminal

From the Windows Accessory group, open Terminal.
From the Settings menu, choose Communications and confirm that all settings are correct.
From the Phone menu, choose Dial.

If there is a conflict on the same IRQ as the modem, the following message will be displayed:

Terminal - Error

The selected COM port is either not supported or is being used by another device.

Select another port.

NOTE: Some of the above problems, such as the modem not initializing and random characters being displayed on the screen, can also be caused by incorrect communications settings. Make sure that all settings, including the Baud Rate, IRQ, and Base I/O Port address in the Windows Ports Control Panel, are set correctly.