My cisco driver com3 port stopped working on windows 10, so I uninstalled the cisco driver. After I rebooted, and reconnected the usb console cable, the native windows usb-serial driver loaded, and a new com3 port appeared. That port works just fine with securecrt with standard 9600 baud settings, so I guess we don't need the cisco driver. fwiw.
You still need to install a driver on your laptop to use the USB interface as a serial communications port. Don't worry that this link shows the download location for 3900 ISR G2 routers. The same utility works for the entire ISR-G2 line. The latest version of the USB Console Software is version 3.1 The filename of the software is "Cisco_usbconsole_driver_3_1.zip" and the current version was release on Jan 20, 2010 with a file size of 14692.83 KB (15045453 bytes).
With the help of a colleague, we narrowed the issue down to windows using a default usb to rs232 driver rather than the cisco one I had installed. The big clue came when I tried using putty inside a VM and it worked, while on the host OS I was still getting error 1450.
First, disconnect the blue Cisco USB console cable. Reinstall the Cisco USB console drive using setup(x64).exe from the Windows_64 folder which was extracted from file Cisco_usbconsole_driver_3_1.zip. 2b1af7f3a8