How can I organize user access to the computers of two departments at the same time, so as not to turn off the network?

Question

Computer networks

Hello!
Office. 2 departments, not connected to each other
1 department router with Wifi 192.168.1.1 (DHCP) (there is access to the router)
2 department router with Wifi 192.168.64.1 (DHCP) (no access)
user (1 computer) one wired network with 2 departments , and a wireless network with 1 department (wifi),
so he switches between these two departments (turns off one network card, turns on the other), because he needs access to the remote desktop and a shared folder in each department.
I want to stretch the cable from department 1 to the user and connect it to the second network card in the computer, throw out the Wi-Fi.
How can I organize user access to the computers of two departments at the same time, so as not to turn off the network?
Only 1 has access (Wireless Router Model TL-WR940N/TL-WR941ND)

Answer 1

And what makes you turn off the network when you connect to another?
The addresses in the networks are different, they do not conflict with each other, so access will be simultaneously to both in the current configuration when connected at the same time.
It is only necessary that both network adapters be on the computer at the same time.

Answer 2

WiFi or cable doesn't matter.
You need to set up routes on the user's computer so that Windows signs through which map where to go.
Although this usually works fine with the default route as well.

Answer 3

Thank you! I don’t know why the previous admin made such a hemorrhage to the user, he switched clearly according to the instructions, even wrote the procedure in his notebook).
I threw the cable, put the second network one, all the auto settings - everything works!