Setting up a network

Hi,

I have 4 computers that I would like to be able to network, 3 are Windows 10 and the fourth is a Ubuntu box we use for backup. There is no problem networking to the Ubuntu box from any of the computers. The other 3 computers, listed in order of importance are mine (1), my wife's (2) and the workshop (3).

#3 can access #1 and sees #2 but is unable to get into her files.
#1 can access #3 and sees #2 but is unable to get into her files.
#2 can access #1 and #3 but it asks for a user name and password for both computers.

I have attempted to share her files with everyone, after several minutes up pops "Can't share this folder"!

Any help would be appreciated.

Jim

If possible, for the Windows computers, you want to use the same username and password combinations (since these are likely workgroup computers and not on a domain). Are they all connected to the same router?

Unfortunately we're old and set in our ways, I've disabled asking for a password.

#1 & #2 are connected (cat5) to the same router/switch combination, #3 is wireless to the same router.

I went into the Control Panel/Network and Internet and turned off Password Protected Sharing, this enabled #2 to have complete access to both 1 and 3, after doing a Share with everyone on the Users. Tried the same thing on #2 and received this: "Your folder can't be shared". Any ideas?

More info. My computer (#1) has a couple of VMs set up, the Windows 7 Home Basic machine has no problem accessing any of the other 3 computers as well as the Windows XP Professional, no problem, I just can't access her computer (#2) from mine or #3. Bizarre!