How to enable debug of dhcp client on Windows 7
Solution 1:
Go to Event Viewer, Applications and Services Logs, Microsoft, Windows, Dhcp-Client, Microsoft-Windows-DHCP Client Events/Operational.
By default this trace log will be empty, because you need to enable it by clicking on “Enable log” on the right side.
Source: http://texhex.blogspot.be/2011/12/debugging-dhcp-on-client.html
Solution 2:
Windows Event Viewer (eventvwr.exe) will capture events/error generated by the DHCP Client, here you'll be able to see when and if a address was requested (DHCPREQUEST) and what the reply from the server was (DHCPACK / DHCPNACK) (These events are in the system part of the Eventviewer utility)