Hi
With modern windows you can set up networks as home business and public
If you don't share files with other PC or devices you could change to public network to stop your files being shared
Most modern router/ wireless systems have white lists and blacklists
Blacklists can be bypassed by changing the MAC address (spoofing)
White lists have the MAC address of all devices you know you own
Usually a label on base of laptops
This is a nuciance if you have visitors who want to use your wireless system
So far better to have high security with long password on network
https://en.m.wikipedia.org/wiki/Wireless_security
I forgot to say ensure router is protected by maximum security
Change SID so it does not show model make or family name or address
Make sure password for admin account is not admin or other default
Disable remote internet admin login
If possible disable wireless. Admin login
( you need to connect by network cable for admin )
Regards
Mike Barnes