How to set shared files permission across a network?

I am trying to set permissions to a shared folder. Let's say the shared folder is in computer A. I want computer B and C can only read the folder but computer D can delete the folder. I don't have a server (so no domain) but only workgroup.

I know how to share the folder but don't know how to assign the permissions to network users. In the security tab of shared folder properties. I can only add the local machine users to assign permision (read, write, execute.). I want add workgroup users permissions too. Is that possible? Thanks for the help.

Well...since your running in a workgroup with no domain, there is no such thing as a network user in that case.

The other major problem is that you're talking about restricting access to computers, but CIFS (shared folders) and NTFS (filesystem) permissions only deal with users, not computers. (While it's true that you can add a machine object to an ACL, that only works in a domain, and it only grants access to the Local System account for that computer, not the entire computer and all its users.)

What you can do is to create a unique account for each server (but don't use the server's actual name, which isn't supported). You will need to create this same account (the exact same account...same username...same password) on both the source server as well as the destination server. This will allow that user to authenticate. You can then assign that user to any share/disk permissions (you must configure both) to allow him access. Repeat this for each server that needs access and youre getting close.

Now here's the catch. Remember how I said permissions are user based, not per computer? What this means is that whatever is attempting to connect to the server will need to be running as the user you created above. So the access only works for that user, not the entire computer. That's the only way I'm afraid.

Your other option (better imho) is to implement a domain and use Active Directory to assign permissions. But this still won't give you "computer-level" permissions, only users.

No, it isn't possible. ComputerA only recognizes user accounts in its own local user account database. What you'll need to do is to create user accounts on ComputerA for the users of ComputerB and ComputerC, set the appropriate Share and NTFS permissions on the share on ComputerA, and inform the users of ComputerB and ComputerC of which user account credentials they should use when accessing the share.