USB to serial RS232.?

Question

Is there a way to change Com port number?By default, most USB to serial converter will have com6 or higher.How can I change it to Com1 because my programming software accept only Com1 for connecting a device.
Thanks

I am using Acer travelmate laptop PC with XP professional OS and trying to connect an old PLC whose program has only Com1.

Thanks Alex_S for the answer.But I got a prompt when I click port properties/Advance.The prompt says"You must have write privileges in the registry for this device in order to modify the device's advanced settings."

I don't know what to do.
Any one can help?

I tried on my desktop PC , port number was able to change to any free number.

I removed the converter and reinstall it. I can change the com port number now.But COM 1 is still occupied and cannot make it free.Modem and blue tooth use com3 & com4 respectively.
Could not find any other device which is using com1.
Any on got idea how to do?
Thanks

Answer 1

recently answered exhaustively about serial ports & serial communication
http://answers.yahoo.com/question/index;_ylt=AoS4mcAh81tSxNGrKU2etOTsy6IX?qid=20070419061840AAFqRdG&show=7#profile-info-lB732Tiyaa
u may get some clues

i face no such problem, i am able to get com1 to com4 with no troubles whatsoever

my troubles are that even after getting correct com port number, i am not able to establish comminication for most times

my advise to you would be to get a pc with a built-in serial port., & not try usb to serial converters

give me details of device, computer, operating system & programme u'r using
i believe you are trying parameterising a drive or plc

i will sure try my best if i can ...

i have plenty many tools to handle com & irq ... but mostly dos based, ms-dos i mean
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siemens s5 ?
are you using step 5, in that case i can suggest you a better program
>> plc, make & model + communication software please
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checkout, could be issues with file system
ntfs / fat32 or even fat16
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http://www.freedownloadscenter.com/Best/port-finder-xp.html

Answer 2

"You must have write privileges in the registry for this device in order to modify the device's advanced settings."
You can either try to change the properties within the registry to allow read and write or try changing them from the properties page of the device itself.
Another option would be to manually install and set it up by selecting advanced setup and from there you should be able to change the settings to whatever you need, of course you do also need to make sure that there are no other devices listed as using the com1 port or you will get conflict errors and it will not allow you to change it.

Answer 3

To change com port number in windows xp, go:
start-settings-control panel-system-hardware-device manager-ports.After that find in list of ports your usb to serial port (com n, n>=5) and right click on it and go to the properties-port settings-advanced. Here you can change a port number.