Would be helpful to have some details about your network, PC, etc.
In the interim, press the reset on the back of the DNS and then turn the unit off. Connect the DNS directly to the NIC on your PC using the Ethernet cable supplied. Set the IP address on your PC to:
IP: 192.168.0.100
Subnet: 255.255.255.0
Gateway: 192.168.0.1 (or 192.168.0.32)
Turn the DNS on, open your browser and navigate to:
http://192.168.0.32
... this is the 'self-assigned' IP when no DHCP server is present.
Let us know how you make out.
Cheers,