I'm installing a new computer and it is asking for the network security key for our router so we can connect to the internet. We don't seem to have the network security key.

Network Key (WEP, WPA, WPA2 Encryption key)To connectyour computer to a wireless router, you click the Refresh networklist, then Choose your wireless network and then click Connectto your secured Wireless Network, it will asks for a Network Keybefore allowing you to connect into your wireless network. This NetworkKey is either the WEP, or WPA or WPA2 Encryption key that is used toconfigure the Wireless Router. The Passphrase is an alternate way tosetup the Encryption key.
When you are requested for a Network Key, you can just enter the Passphrasethat was used to configure the Encryption key in the wireless router.http://www.fixya.com/support/r5270415-network_password_network_addressFor information on securing your wireless network,configuring the wireless router and configuring the wireless card in thelaptop/computer, please click on this link and follow my instructions :-http://www.fixya.com/support/r3559128-wireless_router_security

To connectyour computer to a wireless router, you click the Refresh networklist, then Choose your wireless network and then click Connectto your secured Wireless Network, it will asks for a Network Keybefore allowing you to connect into your wireless network. This NetworkKey is either the WEP, or WPA or WPA2 Encryption key that is used toconfigure the Wireless Router. The Passphrase is an alternate way tosetup the Encryption key.
When you are requested for a Network Key, you can just enter the Passphrasethat was used to configure the Encryption key in the wireless router.http://www.fixya.com/support/r5270415-network_password_network_addressFor information on securing your wireless network,configuring the wireless router and configuring the wireless card in thelaptop/computer, please click on this link and follow my instructions :-http://www.fixya.com/support/r3559128-wireless_router_security

When you clickRefresh network list, then Choose your wirelessnetwork and then click Connect to your secured Wireless Network, itwill asks for a Network Key before allowing you to connectinto your wireless network. This Network Key is either the WEP, orWPA or WPA2 Encryption key that is used to configure the Wireless Router. The Passphraseis an alternate way to setup the Encryption key.
When you are requested for a Network Key, you can just enter the Passphrasethat was used to configure the Encryption key in the wireless router.http://www.fixya.com/support/r5270415-network_password_network_addressFor information on securing your wireless network,configuring the wireless router and configuring the wireless card in thelaptop/computer, please click on this link and follow my instructions :-http://www.fixya.com/support/r3559128-wireless_router_security

Is it asking you for wireless network key?
You need to check the wireless settings of your router.
Connect one computer to the router with the Ethernet cable.
OPen the setup page of the router and check the wireless settings of your router.

The question seems incomplete or not clear but If you are trying to access a secured internet connection at your home or cafe through wifi connectivity, it will ask for the secured password or security key. If it is your home connection ask the person who set the internet connection, if is at a cafe, wifi spot ask the service provider. Hope i understand your question rightly.

Power on your Wii console and press the A Button on the Wii Remote to reach the Wii main menu. Use the Wii Remote to select the "Wii" button.

Now, select "Wii Settings" to access the "Wii System Settings" menu.

Using the arrow on the right side of the screen, scroll to page two and select "Internet."

Select "Connection 1: None"

(Don't see "None" in Connection 1? Click the Connection 1 button, then choose "Clear Settings.")

Click on "Wireless Connection" and then "Search for an Access Point."

(Are you using a wired Internet connection to your Wii console? If so, click here for specific help.)

Select "OK" and the Wii will display all the wireless networks it finds.

Select the wireless network that is yours.

(If you're not sure which is yours, or you don't see any wireless networks, click here.)

Asked to enter a security key?

If you are prompted to "Enter the Password or Key," then the wireless network you are trying to connect to has wireless security turned on. You will need to type in your security key or password and select "OK."

Don't know your router's security key?

Let us help you find your router's security key. Select the brand of your router below and we'll provide you with the default information for that brand!

Linksys Netgear DLink

Belkin Apple 2Wire

All other brands

Select "OK," "Save Settings," and then "Yes."

The Wii console will run a connection test with your wireless network when the test is completed. You should see the following screen:

As long as you see "The connection test was successful," the "Wii Support Code" does not matter and can be ignored

The connection test was successful - Then you're almost done! After your connection test, the Wii console will check if there is a new Wii System Update available. Once you select

"Yes" and "I Accept," the Wii will begin to download any available updates. Click here to find out what's next!

The connection test was not successful - If the test was not successful, you will receive an error code.

Error Code 51330 or 52130: This means the security code you entered into the Wii is not the same one your router is set to. Look in your router's settings and try again. Please refer to step seven (7) above for more information.

All other error codes: Try our error code troubleshooting where we have detailed information on many common error codes. (You can ignore any "Wii Support Code" you receive on a connection test.)

If you need further help, reach me via phone at https://www.6ya.com/expert/eric_5b00a5ceab1c0cd2

Power on your Wii console and press the A Button on the Wii Remote to reach the Wii main menu. Use the Wii Remote to select the "Wii" button.

Now, select "Wii Settings" to access the "Wii System Settings" menu.

Using the arrow on the right side of the screen, scroll to page two and select "Internet."

Select "Connection 1: None"

(Don't see "None" in Connection 1? Click the Connection 1 button, then choose "Clear Settings.")

Click on "Wireless Connection" and then "Search for an Access Point."

(Are you using a wired Internet connection to your Wii console? If so, click here for specific help.)

Select "OK" and the Wii will display all the wireless networks it finds.

Select the wireless network that is yours.

(If you're not sure which is yours, or you don't see any wireless networks, click here.)

Asked to enter a security key?

If you are prompted to "Enter the Password or Key," then the wireless network you are trying to connect to has wireless security turned on. You will need to type in your security key or password and select "OK."

Don't know your router's security key?

Let us help you find your router's security key. Select the brand of your router below and we'll provide you with the default information for that brand!

Linksys Netgear DLink

Belkin Apple 2Wire

All other brands

Select "OK," "Save Settings," and then "Yes."

The Wii console will run a connection test with your wireless network when the test is completed. You should see the following screen:

As long as you see "The connection test was successful," the "Wii Support Code" does not matter and can be ignored

The connection test was successful - Then you're almost done! After your connection test, the Wii console will check if there is a new Wii System Update available. Once you select "Yes" and "I Accept," the Wii will begin to download any available updates. Click here to find out what's next!

The connection test was not successful - If the test was not successful, you will receive an error code.

Error Code 51330 or 52130: This means the security code you entered into the Wii is not the same one your router is set to. Look in your router's settings and try again. Please refer to step seven (7) above for more information.

All other error codes: Try our error code troubleshooting where we have detailed information on many common error codes. (You can ignore any "Wii Support Code" you receive on a connection test.)

If you need further help, reach me via phone at https://www.6ya.com/expert/eric_5b00a5ceab1c0cd2

Network security key is a encryption key.

Theencryption key secures your data from unauthorized access. The router's password is a Passphrase or the WEP or WPA orWPA2 encryption key. The Passphrase generates the WEP or WPA or WPA2 encryptionkey and this is in the router's wireless settings. To connect to your wireless router, it needs the router'swireless settings configured ie SSID, WPA or WPA2 encryption key and also thewireless cards in all the laptops and or computers needs to be configured withthese router's wireless settings. Then the laptops and desktop computers cancommunicate with your wireless router.

Router password is the password to access the router settings.
SSID is the network name. When you try to connect to the wireless network on your laptop, you will see this network name.
If your network is secured network then it will ask you for the network key or the password. You need to enter the ' security key '.

Click Here for step by step by instructions

It would seem that your network is actually wireless. What you could do is double check the security key for your wireless network on your router or you could check the other 2 computers, if they are connected wirelessly, for the security key. Then use that security key on your new computer.