Configure the settings in the router first...
It seems that what you are doing is trying to set the configuration on your wireless adapter without setting them up on the router first. You get into the settings for your router by going through your web browser (Firefox, Internet Explorer, etc.). Go to the configuration page found at 192.168.0.1, log in as admin, and leave the password field blank (unless you have been in this page before and have set a password). After this, click on the Setup button at the top of the page, then select the Wireless Settings tab on the left. You will see a list of various settings come up in the main part of the page.
What I will advise you to change are the Wireless Network Name (aka the SSID) to something other than Dlink and that is not easily identifiable to you (I often set the SSID to something meaningful for the client but meaningless to just about anyone else), make sure that channel auto-scan is checked, select Super G with Dynamic Turbo (this will potentially give a performance boost if all adapters in the network are compatible with the increased performance parameters), and if you want even better security, select Enable Hidden Wireless. This last option will hide the SSID from displaying over the airwaves: someone will have to know the name of your network before even being able to get a chance to connect to it.
Just beneath all this is the Security Mode option. By default, it is disabled but can be set to WEP (the weakest but most compatible and good enough for most people), WPA-PSK (better than WEP but not as secure as the final option and not compatible with all adapters; most nowadays will speak WPA, though), and WPA2-PSK (the most secure but also the least compatible as not all adapters have the capability to understand this encryption protocol). Ignore the other options that are labelled plainly as WPA and WPA2. Those are for corporate networks that have a device known as a RADIUS server. For ease of setup and greatest compatibility, select WEP. Once you do this, you will be presented more options. The first (Authentication) should remain at the default of Shared Key. After that, you can choose either 64-bit or 128-bit for the WEP Encryption. If you wish to keep things simpler, choose 64-bit as that requires only a 10-digit hexadecimal key while 128-bit requires 26 digits. (Hexadecimal numbers are numerals 0 through 9 and capital letters A through F--thus giving a total of 15 values before reaching the hexadecimal value of 10, which equates to 16 in our standard base-10 world.) Examples of valid 64-bit and 128-bit keys are 0A29CBAFE5 and FA973CD29612345FDCBA73F415, respectively. Unless you enjoy the painstaking complexity of a long number such as the second number above, stick with 64-bit WEP. :-) The next option (Key Type) can be either HEX or ASCII. The difference is that if you select ASCII, while you don't need to type keys as long as what I demonstrated, they are not as easy to remember because the 5 or 13 characters (for 64-bit and 128-bit ASCII keys, respectively) get converted into 10-digit or 26-digit key codes by the router. I advise leaving the selection at HEX and choosing your own code that means something to you. (A pattern I often use for my clients is to use their street address: the first four digits represent the numeric part of the address, the next represents the name of the street with the letter A being the value used if the street address starts with any letter beyond F, and the final five digits are the client's ZIP code. It's easy for the client to remember but not something that a typical passerby would figure out in short order.) The next option is for the Default WEP Key with the default being Key 1. Just leave it be and then type your preferred key code into the field marked WEP Key 1. Once you do all that, click on Save Settings. The router will probably reboot itself but will return to service in about 30 seconds or so.
The options for WPA and WPA2 are fewer: Cipher Type (which defaults to Auto; go ahead and leave it at the default), PSK/EAP (select PSK), and then two Passphrase fields (the second being to confirm the first, just like a person does when entering a new password). The value that is entered must be between 8 and 64 characters. Valid characters are just about anything visible on the keyboard (e.g. any letter, punctionation symbols, numbers, etc; spaces are valid as well). Make sure to enter the exact same passphrase in both fields. Click Save Settings to save them to the router, at which point it will probably reboot... (You heard this spiel up above, huh?)
After you have done all this, go to your wireless computers and set up their adapters to use the options you have set on the router: the same type of encryption and the same key/passphrase. Once you have done this, everything will be communicating with wireless security.
If you have any other questions, please feel free to drop me a line. I'm glad to help.
|Sources: 22 years of experience as a computer technician and 20 years of experience owning a computer sales and services business|