Article ID: Q500002
The information in this article applies to:
For Direct I/O, version 4.3 and above see article Q500004.
Normally the serial port (COM) is controlled by
Windows NT. Software needing direct access to the serial ports registers
does not run properly.
Follow the steps given below to configure your system properly:
Depending on your configuration you may notice some error messages at startup stating that the device serial.sys cannot be started. This occurs in cases when you have grabbed the only serial port built into this PC. You can get rid of these messages by changing the startup mode of these devices to Disabled.
You cannot utilize a serial port grabbed by Direct I/O from within Windows NT. Only one device has control over a given hardware resource, either serial.sys or Direct I/O.
On some Windows 2000 systems you might fail in controlling the serial port due to ACPI conflicts. Please read Q700005 for further information.