How to Install a Wi-Fi Antenna on a Compaq Presario R4000
The Compaq Presario R4000 line of laptop computers comes with a WiFi card already installed that has a built-in antenna for accessing WiFi hot spots and wireless home networks. If your Presario laptop is no longer able to access wireless Internet sources even though you haven't changed any settings, your WiFi card has probably stopped functioning. You can replace the WiFi card by opening up a small compartment on the bottom side of the laptop.
Click on the "Start" button at the bottom of the computer's desktop screen and then choose the "Shut Down" option. Wait for the Compaq Presario laptop to completely power down and then shut the top LCD screen lid. Turn the laptop over so that you can see the battery on the bottom side of the case.
The bottom of the laptopHold down the battery release latch and then pop the battery completely out of the laptop case. Set the battery aside. Locate the square area on the lower left side of the case that has two screws side by side.
Remove the two screws and set them in a container for safe storage. Slide a fingernail or the edge of a flat head screwdriver underneath the seam of the plastic cover near where the screws were located. Lift the cover up and then pull it entirely off the laptop case.
Grab both sides of the exposed wireless card and gently pull it out of the laptop at a 30-degree angle. Set the card aside and get your replacement WiFi card. Check the notches on the bottom of the new WiFi card and compare them with the notches on the open port in the laptop case.
Slide the new WiFi card directly into the port until it clicks. Set the plastic cover back onto the case and then reconnect the two case screws. Push the battery back into the slot until the battery latch clicks. Flip the Compaq Presario laptop back over and open the lid. Power on the laptop and open your web browser. Attempt to access a website to make sure the wireless card was installed properly.
Article Source: ehow.com