Display message "An old device driver is already installed" during installation

An older version of the serial communication driver is already installed.
Uninstall the installed serial communication driver, and then install it again.

In the case of "COM-DRV for COM-4xx-USB" was installed

The way to uninstall depends on the installed the serial communication driver version.

Serial communication driver	The way to uninsstall
COM-DRV(WDM) Ver.10.00 or later	Please refer to [Setup Driver Environment]-[Modify and Uninstall]-[Uninstall] topic.
Windows Serial Communication Driver Ver.9.20 or earlier	Please refer to "Uninstall for Old version (Board)" topic.
Windows COM-DRV for COM-1xx(USB)H Ver.3.10 or earlier Windows COM-DRV for COM-4xx-USB Ver.3.10 or earlier	Please refer to "Uninstall for Old version (USB)" topic.
Windows Virtual COM Driver Ver.4.70 or earlier	Please refer to "Uninstalling Virtual COM Driver for Old version" topic.
Serial Communication Media Converter Softwaer Jan.2025 or earlier	Please refer to "Uninstall Serial Communication Media Converter for Old version" topic.