Best way to access 3 computers from another room

I am going to be out of commission for a couple of weeks due to surgery.

I'm buying a new Win10 laptop.
What's the best software to access our 3 Win7 computers from another room?

#1 computer is my wife's stand alone with 1 monitor.

#2 and #3 are both my computers (1 for trading etc).
I have double monitors and two manual switches where I can switch one or both monitors to either computer.

What's the best software to install on the new laptop (using WIFI) that will allow me to view each computer's configuration (1 configuration at a time) but if it has double monitors I need to be able to view each monitor separately (using a toggle key)?

If #2 or #3 has double monitors I need to be able to go quickly back and forth between each monitor on that particular computer.

It is important that each separate monitor appear full screen when toggled on.

Thanks for any help

You don't mention whether the computers are currently networked or not. If all of the computers are currently connected via a network and you have a wifi capable router, then you should be able to connect to the network with the laptop via wifi.

As for remote access/control of the 3 computers, RDP or Remote Desktop Protocol has been suggested and will work fine provided that all 3 of the remote computers are running Windows 10 Pro or Enterprise. If they are running plain Jane Windows 10 then RDP is NOT a workable solution.

The software I would recommend for you to use (it's free) is called TeamViewer. It's very easy to install and use. Home - TeamViewer

It's not the laptop that needs Win 10 Pro, it's the remote computers.