How do I access another domain?
By default the credentials used for the Machine are applied as credentials for Domain remote Machine is located in. It is displayed in Log on to field of credentials edit. In case you need to use the remote Machine's local account or the account from the Domain that differs from the provided by default you should specify the Machine or Domain, account is located, in name explicitly. Log on to field value is then changed to help you understand clearly which Domain credentials are used.
To do the described you should input a value of the following format to the User Name field of alternate credentials pop-up edit.
<Domain name>\<User name> - for the explicit specification of Domain account
<Machine name>\<User name> - for the explicit specification of the remote Machine account
Domain provided by default, if applicable, is displayed in Log on to field of credentials alternate pop-up edit.