For Most HP models
Use the menu to navigate to Setup, then Network, then Wireless Radio (on some models, this is towards the bottom of the scrollable menu). Turn the Wireless Radio OFF.
HP Laserjet P1102w
Press and hold the “wireless” image button on the left-hand button panel for 5 seconds to turn the light out and service off.
HP Photosmart D110
Some models may allow you to press the blue “wireless” button on the bottom front of the printer to turn the light out and service off. You may need to hold the button for 5 seconds to turn the light out.
If this is not successful, use the menu to navigate to Settings > Wireless > Wireless settings > Disable Wireless > OK
HP Photosmart C4780
From the front panel, choose “Scan”. Scroll up or down to find Networking. Select this, then turn off Wireless.