Log In

Come Join Us!

Are you a
Computer / IT professional?
Join Tek-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Tek-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.


conflict between the serial port COM1 and the mouse

conflict between the serial port COM1 and the mouse


Could you please help me to resolve the problem that I'm encountering since a long time
I have a data coming through the serial port COM1 almost every 3 seconds (Real-Time data) and I'm using a USB mouse which plugged in one of the USB ports
When I reboot the machine the mouse start moving everywhere, and I can't take control of it.
it seems that serial port COM1 is considered as the mouse signal
Knowing that even if I remove the mouse, the problem reside

Could you please advise in how I can fix this issue?

I will appreciate your help
Thanks in advance

RE: conflict between the serial port COM1 and the mouse

I don't think this is an operating system spefic problem.  You could see if your bios has any options or settings to 'disable legacy mouse' or something similar.  You might want to also ask in forum602: PC hardware - General discussion

RE: conflict between the serial port COM1 and the mouse

In device manager, under mice and pointing devices, does XP show you have a serial mouse connected on com1? If so you might try disabling it there.

Another option might be to disconnect your data feed during XP startup so it doesn't detect the feed as a mouse, then reconnect after bootup is complete and start your data feed app.


RE: conflict between the serial port COM1 and the mouse

thanks you for your feed back
Honestly, I need to keep the mouse connected, I can't disable it as I need it for remote control.
What I'm doing right now is the disconnect the serial port, reboot the machine ,and then plug the serial cable again after the startup, and it's work, but I don't want to do it manually each time I reboot.
Is there any command that I have to write in the boot.ini file to avoid detecting the mouse at the startup?

Thanks for your help

RE: conflict between the serial port COM1 and the mouse

Go into the CMOS setup utility for your machine and change the COM port address to COM2 or something else.  Back in the olden days, COM1 and COM3 tended to conflict and COM2 and COM4 did also - that was due to the sharing of an interrupt (control line) between the pairs of ports.

You could also go in to the control panel - system - device manager - COM & LPT ports and select that port.  Go into its properties and select another COM address in there.  I guess that would be the first place I look to make the change.

RE: conflict between the serial port COM1 and the mouse

Thanks Donb01 for your suggestion but even if I change to COM2 with another address, as soon as I reboot it will detect the signal coming from any COM and it will assume it as a mouse
Anu other suggestion

Thanks again

RE: conflict between the serial port COM1 and the mouse

I was asking if device manager showed TWO mice, one serial and the other USB. I don't want you to disable the USB one, just the serial one. Hopefully that will stop XP from treating input on that port as mouse events.


Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Tek-Tips Forums free from inappropriate posts.
The Tek-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Tek-Tips forums is a member-only feature.

Click Here to join Tek-Tips and talk with other members!


Close Box

Join Tek-Tips® Today!

Join your peers on the Internet's largest technical computer professional community.
It's easy to join and it's free.

Here's Why Members Love Tek-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close