Windows 10: COM Port Issue on Windows 10 20H2 update

We have some software that utilizes COM serial port. We are having issues with communications thru the COM port slow communication after updating to Windows 10 20H2. Version 1909 works flawlessly. It was also noted that the problem only is on 20H2 Windows 64 bit. 32bit Windows 20H2 works ok. The application is a 32bit application.


We tried different COM port drivers, USB to Serial, Ethernet to Serial, and all have the same slow communication issue.


I have found others that have had issues with COM serial ports after updating to 20H2. Does anyone know what broke it and how to apply a fix. We've updated to the latest Serial drivers without it fixing anything.


Help.

:)

 

New install Windows 10 (issue solved)

It's good that you're not experiencing any issues. Unfortunately many folks are, a quick Google search will show the same info im offering the OP.

Heres a couple examples:

Here

Here

It's basically what I mentioned above, small issues here and there ,but nothing to end your day.. for the most part.

I know it's anecdotal, but for my experience 95% of the time it's perfectly fine. The issues I've run into wouldn't be enough for me to roll back , but they would be enough (had I not installed it yet) ,to avoid it for another couple weeks which is why I'm suggesting it to the OP

Windows 10 Fall Creators Update problems and complaints

• Installation problems with the Fall Creators Update
• Microsoft Edge problems with the Fall Creators Update
• Drivers problems with the Fall Creators Update
• Experience problems with the Fall Creators Update

keep in mind, as of recently, the FCU is installed on 5% of devices roughly.....

 

Windows update issues

+1

If your wireless router has a built in firewall maybe it's somehow set to block the ports that Windows updates use?

I'd also suggest if it works with it being directly connected then you could try resetting your router to see if this fixes the issue.

That's my 2 cents anyways. *Smile

 

Windows update issues

It works, but I still need to fix it so that way I dont have to plug computers directly to the modem to get windows update to work. It was also blocking me from installing directx.