If your domain does not show up in the domain pick list in the Deployment window of Pack n Deploy this is an indication that your Windows network is not configured to support deployment through this module.
It may be that your network administrator has disabled NETBIOS.
If your domain shows up but you are unable to browse the domain to the computers you may have another issue.
Verify that the target computers have File and Print sharing enabled.
Your organization may have Network Security Policies in place that will prevent you from browsing to domains or computers in this way.