D-Link DIR-451 User Manual page 49

Section 5 - Connecting to a Wireless Network
3. The Wireless Network Connection box will appear. Enter the
same WEP key that is on your router and click Connect.
It may take 20-30 seconds to connect to the wireless network. If the
connection fails, please verify that the WEP settings are correct. The
WEP key must be exactly the same as on the wireless router.
D-Link DIR-451 User Manual 4