D-Link DIR-842 User Manual page 86

Section 4 - Connecting to a Wireless Network
3. Enter the same security key or passphrase (Wi-Fi password) 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 security settings are correct.
The key or passphrase must be exactly the same as on the wireless
router.
D-Link DIR-842 User Manual 82