>A tech guy told me that there could be a needed reset to the network card when going from SMB2, SMB3 to SMB1.
>
>To me this is only a Windows adjustment. So only software and not hardware.
>
>Who is right?

There are severe security vulnerabilities with SMB1. It should not be used with any Windows computers running Vista or later. The only valid reason for still using it is if you must still run XP or earlier machines; in that case, those machines should be segregated to a separate network and have extra protection in place to mitigate SMB1 attacks.

If you're using Vista or later, leave the default SMB2 or later networking in place, and apply the registry modifications.

Changing SMB networking configuration requires, at a minimum, restarting certain services (don't know exactly which ones off the top of my head). A machine restart will certainly address it. Some advanced network adapters with TCP offload may require a hardware restart (e.g. certain servers and high-end workstations) but mid-range or entry level hardware usually won't require a NIC restart.