Utilizing the command prompt and the ipconfig command, you should first determine if the user is receiving an IP within the network's scope. If the user is receiving an in-scope IP address this means that they have network connectivity and the issue likely lies outside of the Link Layer.
Wikipedia
In computing, ipconfig (internet protocol configuration) is a console application of some operating systems that displays all current TCP/IP network configuration values and refresh Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS) settings