Within the Actiontec Advanced Setup for Wireless:
ESSID: whatever (you pick a name)
Wireless Settings: WEP Key
Authentication Type: Shared
Key 1: (type 10 HEX characters consisting of a-f and 0-9)
Start/Settings/Connections (a tab at the bottom)/Main (a tab at the bottom)
Add check to box: Wireless LAN is ON
Settings (a tab at the bottom)
Move slider right or left for desired Power Save Mode
Put a check in the box: Auto turn of WLAN if not connected (specify time limit)
LEAP (a tab at the bottom)
Do not make any changes or add new settings here.
Click on OK at top right which brings one back to the Settings/Conncetions (tab)
Click on the Network Cards icon to reach the Configure Wireless Networks screen.
You will be in the Wireless tab area.
Click on Add New... and with the General tab at the bottom:
Fill in Network name: with the ESSID entered into the Actiontec priviously.
Connects to: The Internet
Do not check the box for: This is a device-to-device (ad-hoc) connection.
Click on the Network Key tab.
Set Authentication to: Shared
Set Encryption to: WEP
Uncheck the box for: The Key is provided for me automatically
Enter the same network key as entered into the Actiontec as Key 1
Set the Key index to: 1
Click on the 802.1x tab.
Uncheck the box for: Use IEEE 802.1x network access control
Click on OK at the top right of the screen, which will return you to the Configure Wireless Networks screen.
In the drop-down box for Networks to access, select: All Available
Do not check the box for Automatically connect to non-preferred networks.
The ESSID of your wireless should now show up in the list of wireless networks.
The status should show up as "Available."
Click on the ESSID for a few seconds and a drop down menu will appear. Select "Connect."
With any luck, the status will change from "Available" to "Connected" and you will be able to browse the Internet!
Other sources of information on the SX-66 phone:
Forums that could be of some help: