First, try to make self ping, or Localhost (127.0.0.1). Check with IPCONFIG /ALL to check the status. If possible flush the arpcache. See the Guest A/c status. Ensure the router is compatible with Windows 7..... Although I am providing the procedure, just carefully observe and ensure the network connection.
If the <a href="http://windows.microsoft.com/en-US/windows7/selecting-a-wireless-router-or-another-wireless-network-device">wireless router</a> compatible with Windows 7, then u can set it up automatically using the latest version of <a href="http://support-in.canon-asia.com/contents/IN/EN/8200709200.html#3">Windows Connect Now or WCN on Windows 7</a> a newly built-in feature.
Now, u can connect network by clicking the network icon. After that, open browser and type as http://192.168.0.1 (as u mentioned, DLink, I guessed) and after login run router’s setup utility.
Now switch to a wireless connection and connect connect other computers to network, follow these steps:
1. Log on to the computer which want to connect to the network
2. Open Connect to a Network by clicking the network icon in the notification area and choose the wireless network from the list that appears, and then click Connect.
Notes: If there is a push button on router, push the button and then wait for a few seconds while the router automatically adds the computer to the network. No security key is required.
Kindly, Look Here for <a href="http://support-in.canon-asia.com/contents/IN/EN/8200709200.html#3">WireLess Connection</a>
Recommend starting simple then moving to the complex: If you HAVE a D-Link router between your server and your ISP connection, why are you doing routing on your server? Seems unecessary and the redundancy is most likely killing your work.
Whats wrong with getting a small switch (unmanaged ones work great) to connect to your PC's / Server and let the router do the routing?