I have a number of Windows 7 machines and I will be damned if I will upgrade to Windows 10. Hence my decision to move over to to LinuxMint

All is going well. However, I am keeping a couple of old machines running Windows 7 for their offline software uses and windows programs I still use.
BUT I can't seem to connect a Linux machine to the windows machine on the network to share various files etc. It is driving me nuts trying to get it to work.
The established windows home network all run windows 7 Pro PC's and the name of the home network is HOUSE
I think this is what windows 7 refers to as the workgroup
On my Linux machines I use Nemo as the file manger. When I click on the Network menu item I can see the shares on the windows home network. For example on a windows machine named hpcomputer I see the drives C$ and E$ which have shared folders within them.
When I double click on C$ up pops the following box:
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Password required for share c$ on hpcomputer
Connect As Anonymous or Registered user
Username
Domain
Password
etc.
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Despite using what I would normally use to access these shared folders via another windows PC, I can't get in using the Linux machine.
I have no idea what it means by Domain. I am assuming this is the workgroup name, which on my windows network is HOUSE
When I also enter the username and password for that windows PC, the pop up box in Nemo simply flashes and reverts back to empty fields and I can't access the windows PC.
I have tried various combinations of empty fields, upper and lower case usernames, etc. but no success.
What am I doing wrong?
Thanks.