Note: Make sure that your wireless security setting is set to being WPA instead of WEP.
Enabling WEP will disable the wireless N feature of your D-Link router. WPA encryption should be used by default as it is a stronger encryption than WEP. WEP encryption on DIR series routers should only be used if you have other devices that do not support WPA.
In the event that you must use WEP, these steps will fix the certificate error.
Step 1: Click on Start, then Control Panel
Step 2: Click on Network Connections
Step 3: Right-click the Wireless Network Connection and select Properties.
Step 4: Click the Wireless networks tab
Step 5: Select your wireless Network name under Preferred networks and click on Properties.
Step 6: Click on the Authentication tab
Step 7: Uncheck the box that Enables 802.1x authentication and click OK.
Tags: certificate, DIR Series, DIR-655, wireless network