Question : User not connecting to a resource on the network

I have a folder in my computer that needs to be accessed by another user in the same domain, but when he tries to open the folder (a shortcut in his desktop) a logon dialog appears, and his username abd password don't work, I've checked the permissions on the folder and the whole unit (D: in this case) and the user has full control over the file and the disk, but he still can't access, not even usin the run syntax \\\d$, how can I set thi up so that the user can access my folders?

Answer : User not connecting to a resource on the network

Also is this computer on the domain if so when prompted for login:

domain\login
password