Service Pack or Virtual Machine broke serial ports

Serial ports work differently after a service pack or virtual machine was
installed. I work for a large organization which pushes updates to all the
employees pc's. January 2004 I completed testing a program that uses a modem
and/or a serial port to connect to a device with a proprietery communications
protocol. I tested the app with Win95, Win2k, and XP with no problems found.
This week a customer is having communication problems with our equipment with
Win2k but Win95 works fine. I confirmed it. In addition I rechecked with my
own system using the same hardware, computer and win2k. The system no longer
worked which worked a year ago, the only changes were pc updates because of
viruses or hackers. So the question is: What happened? Data seems to no
longer be sent out the serial port in one contiguous stream but is broken up.
My fellow programmer had this happen to him last march(2004) when he was
using a C program to talk to his device just fine then it quit after some
update was pushed on his pc. Is there a fix for this?

Microsoft is attempting to release updates that break nothing,
but also to get vulnerabilities patched quickly. I believe that
if you contact them, they will say that if your application is
more important to you than eliminating the vulnerability, then
the fix is to uninstall the offending update, but check with
them. Note the free support numbers here:
http://support.microsoft.com/gp/securityitpro

The web interface is a convenience for users who are ignorant of
how to use a newsreader. Anyone who is willing to avoid
identifying himself as ignorant of how to use a newsreader will
get better attention here.
news://msnews.microsoft.com/microsof....windowsupdate
is a link which will open this newsgroup in your default reader,
which for most Windows users will be Outlook Express.

"pspring" <> wrote in message
news:9A5D5814-4523-4671-B8CC-...
> Serial ports work differently after a service pack or virtual
> machine was installed. I work for a large organization which
> pushes updates to all the employees pc's. January 2004 I
> completed testing a program that uses a modem and/or a serial
> port to connect to a device with a proprietary communications
> protocol. I tested the app with Win95, Win2k, and XP with no
> problems found. This week a customer is having communication
> problems with our equipment with Win2k but Win95 works fine. I
> confirmed it. In addition I rechecked with my own system using
> the same hardware, computer and win2k. The system no longer
> worked which worked a year ago, the only changes were pc
> updates because of viruses or hackers. So the question is:
> What happened? Data seems to no longer be sent out the serial
> port in one contiguous stream but is broken up. My fellow
> programmer had this happen to him last march(2004) when he was
> using a C program to talk to his device just fine then it quit
> after some update was pushed on his pc. Is there a fix for
> this?