No COM ports listed in device manager

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G

Guest

My modem reports an error that another application is using the COM port 3
even when no other applications are running. I looked at the device manager
to switch the modem to a differnt COM port but no COM or LPT ports are listed
at all.
Some other applications that use COM ports such as MS ActiveSyncwork
correctly despite display an error message that COM3 is not availabel at this
time.

Why can't I find COM ports in device manager? Any suggestions on how to fix
this?
 
Frequently the issue is caused by "misinstalling" the modem. The modem
has the Com port but Windows doesn't recognize it. Uninstall the modem
(remove all instances) and then shutdown the PC and remove it. Then
startup the PC. Now read the instructions for installing the modem and
follow them exactly.
 
Chicory said:
My modem reports an error that another application is using the COM port 3
even when no other applications are running. I looked at the device manager
to switch the modem to a differnt COM port but no COM or LPT ports are listed
at all.
Some other applications that use COM ports such as MS ActiveSyncwork
correctly despite display an error message that COM3 is not availabel at this
time.

Why can't I find COM ports in device manager? Any suggestions on how to fix
this?
Click to expand...


Most motherboards still have 2 serial ports installed on the
back plane. They are also known as COM1 and COM2. However, for
Windows to see them, COM1 and COM2 need to be activated in the
bios setup. If COM1 and COM2 were activated at the time when a
modem was installed, the modem becomes COM3 and is enumerated
as such. Even if COM1 and COM2 were turned off, COM3 can still
function when called as it is a "soft" device (i.e., sharing a
device interrupt with another COM device). If COM1 and COM2 were
turned off, then it would not appear in device manager.
 
I had the same problems, couldn’t see any com ports listed in Device Manager.
The following is complements of Paddlefoot on The Geek Elder. It worked, I
could see all the com ports in use and delete all the extraneous ones causing
conflicts.

In Control Panel open System then click on the Advanced tab. Near the bottom
click on the Environment Variables button. Under System Variables click the
New button and enter devmgr_show_nonpresent_devices in the Variable Name
space and enter a '1' in the Variable Value space.
 
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