Denso QB30-SR User Manual page 19

(3) Check that the USB device (scanner) to be connected is not plugged in the
computer, and then click OK.
Note: When installing the serial port driver for the 2nd or the following USB
devices on the same computer, ensure that none of those USB devices is plugged
in the computer, and then click OK.
If the conventional USB-COM device driver version 1.x has been installed, the
message asking for uninstallation of the conventional driver appears. Click OK.
If the message shown at left appears, the conventional driver is running on the
computer. Terminate the application using the COM port of the driver, remove
the corresponding USB device, and then click OK.
Uninstalling drivers is in progress, showing the uninstalling message given at
left. Upon completion of uninstallation, select Finish and reboot the computer.
After the computer reboots, go back to step (1) above again.
(4) Wait for installation of the driver files to proceed.
Note: When installation is in progress, the DOS prompt window appears as
shown at left. Do not close the window since it is not abnormal. Wait for the
window to automatically close.
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