>>>>make an explicit connection to the UNC using WNetAddConnection2() or >WNetAddConnection3(), which allow you to specify a userid and password for the >connection - it's unlikely that the IUSR_machinename account has privileges on >another machine or in a domain unless you've explicitly taken steps to >establish such accounts. IUSR_machinename is a local account, not a domain >account, and won't have domain privileges or corresponding accounts on other >peer stations.
>
>Here is an article I found on this:
>
>http://support.microsoft.com/support/kb/articles/Q138/6/78.asp
>
>Why do you recommend using WNetAddConnection2 or 3?

Because unlike WNetAddConnection, they permit you to specify a domain context, user name and password.