This is a wild guess, but it may apply here. I don't know
if they use a com port like a cell phone does. The only
way you can see the assingments is from a modem, they are
the only ones that have the advanced tab and com port
settings. Other things use them , but do not have a tab
to change them.
goto control panel> system properties> hardware> device
manager> modems, RT click properties> advanced tab>
advanced port settings and look at the com port settings,
see what shows ( in use ) Then see if the rest of this
post applies.
Com 1 and Com 2 are physical ports and have IRQ
assignments 3 & 4 are shared from 1 & 2.
From there the ports are virtual There 256 of them. The
problem is once they are assigned they cannot be deleted,
but they can be un-installed there a trick to do. I had a
laptop that I was having issues with and had gone up to
port 16, from failed installs. The program would not
recognize anything above port 4. When you install
something it is automatically assigned the first open
port, but it goes to the higher # ( if 5,6,7 are open and
8,9 are (in use) it will assign port 10 you install
something, thus the problem.
How I corrected it was to take a USB modem and keep
installing it and go into the device manager and change
it
to a port that showed (in Use) that I knew was not, then
when that port is accepted go back in and uninstall it.
Go to the advanced tab> advanced Port settings>
Com port # and then force it to the one you want out
select it> ok, then back out. Then un-install it,
reinstall it and repeat till you get them out.
Most PC's have two motherboard based Serial (Com) ports.
Com1 (Serial Port A) and Com2 (Serial Port B). Com Ports
have two parameters, Address and IRQ#. They are enabled
& configured in BIOS, usually under the Integrated
Peripherals category. By means of multiplexing, the
number of Com Ports can be extended. Com3 and Com4 have
different addresses but share resources with Com1 and
Com2.
PCI modems have their own dedicated Serial port on the
card itself. This usually conflicts with the motherboard
based Com ports. What you need to do is, enter BIOS and
disable the on board ports. Open Device Manager, View,
tic "Show Hidden Devices". Expand the Ports category and
Uninstall the grayed out Com1, Com2. Afterwards your
modem will have exclusive access to any address/IRQ (3 or
4) that it needs.
