Windows 7 on Compaq 610 cannot connect to DLink 2750U wireless network

[phoenix]

My mother's Dlink 2640U was damaged during a recent storm, so I bought her a Dlink 2750U to replace it.
Unfortunately, although both my Kindle and my Nintendo 3DS can connect to the router wirelessly, her Compaq 610 laptop will not connect to the wireless network. I'm convinced that Windows can see my wireless network, as it shows up at full strength in the wireless adaptor widget in the system tray. When I click on the connect button here, "Connect to a network" returns the message: "Windows was unable to connect to [SSID]"

I have MAC address filtering enabled, but have added the laptop's physical address to the relevant list, and checked it several times to make sure that I did not make a mistake when entering it.

I have also made sure that I entered the WPA2-PSK AES key correctly.

Please could you try to help me to get this up and running for my mother-she is missing her internet connection.

Thank you.

 

[Sgt. Draike]

Check the Device Manager for valid Wireless card entry.
http://www.ezlan.net/Win7/net_dm.jpg
If there is No valid entry, delete any Bogus Entry, and re-install the Wireless card's Drivers.
Check the Network connections to make sure that you have a Wireless Network Connection Icon/Entry, and that the Properties of the Icon (right click on the Icon) are correctly configured with TCP/IPv4 protocol in the Network Connections Properties.
http://www.ezlan.net/Win7/net_connection_tcp.jpg
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Make sure that if there is a vendor's Wireless Utility the utility is Not Running together with the Windows native Wireless utility.
Make sure that No Firewall is preventing/blocking the Wireless components to get to the Network.
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Working TCP/IP stack should look this way.
Right click on the Wire card Network Connection, choose Status, Details, and see if it got an IP and the rest of the settings.
http://www.ezlan.net/Win7/status-nic.jpg
Description is the card manufacturing data.
Physical address is the card's MAC number.
The xx should be a number from 0 to 255 (all xx same number).
yy should be from 0 to 255
zz should be from 0 to 255 (all zz the same number.
The lease date should be valid to the current time.
*Note 1. IP that starts with 169.xxx.xxx.xxx is not valid functional IP.
*Note 2. There might be an IPv6 entries too. However, they are not functional for Internet traffic or LAN. They are needed for Win 7 special HomeGroup configuration.
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If everything above is OK you have to be able to connect to the Router. A Window that says Connected does not means that your are really connected. Connecting to the Router means that you can enter the Router's core IP into an address bar of a browse, be able to connect, see, and configure the Router's menus. If it does not connecting to the Router log from any computer that can connect to Wireless Router with a Wire, disable the Wireless Security, (make sure that the Wireless broadcast SSID) is On, and try to connect with No Wireless security.
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I really checked and configured every thing and it does Not work.
Software Firewall application that is Not configured to allow local traffic (between the computer and the Router is a possible issue too.
some 3rd party Software Firewalls keep blocking aspects of Local Traffic even it they are turned Off (disabled). If possible configure the Firewall correctly, or totally uninstall it to allow clean flow of local network traffic. If the 3rd party software is uninstalled or disables, make sure that Windows native Firewall is On .
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