Network not connecting or something

So this is a complex question, mostly about network passwords( and I am a dummy about networks) :

I had a 'professional' (owner of a computer shop) install a network between three computers--two win 10 pro desktops and a win 10pro laptop. The laptop and one of the desktops live in the house. The other desktop lives in a shop building about 50 feet away.

When I try to open the network from the shop computer I get a window that asks for a password. I don't know it. When my wife tried to print to a networked printer from her laptop, the laptop saw the printer but the print job never even initiated. At one point, she accessed netshare (?...some of this is second hand) and got a message that said the password was expired and "no longer valid."

So I guess the fundamental question is whether and how (I have administrative rights) I can recover or reestablish working passwords of each node of the network.

??

The shop is it on wifi or cable if its wifi its the wifi password its asking for the person who installed should have told you or you can change it on the router

Caledon Ken said:

So it really isn't a network password. It is asking you for Windows Credentials to log on to the desktop.

Well, IIRC, I think you're right but it's Sunday and my birthday (74) and I've got other fish to fry than go out in the shop and fire it all up.

So, briefly, is there an app or utility to recover windows credentials?