A wireless adapter can either be an external or internal card that is attached to the computer and enables it to connect to wireless networks. There are a myriad of reasons why your wireless adapter may stop working on your computer, including driver issues and physical installation, among many others.
Install the driver of the wireless adapter to your computer. Place the wireless adapter installation disc into your computer's optical drive and follow the instructions that will flash on your screen. If you do not have the installation CD, download a copy of the driver from the manufacturer's website. If you are sure that the driver of the wireless card is installed, the driver of the device may need to be updated. Proceed to Step 2 for instructions on how to update the driver or Step 3 for instructions on how to uninstall and reinstall the driver.
Click "Start," right-click "My Computer" or "Computer," click "Manage" and click "Device Manager" in the left pane of the window that opens to open the Device Manager. Click the plus sign beside "Network Adapters" to reveal your wireless network adapter. Right-click the name and select "Update Driver."
Uninstall the driver of the wireless adapter and reinstall it to the computer. To uninstall a driver, navigate back to the Device Manager window. Double-click the wireless adapter's name, click the "Driver" tab at the top of the window and then "Uninstall." Follow the instructions on your screen until the driver is uninstalled. Reinstall the driver to the computer by running the installation CD. If you do not have the installation CD with you, download the driver from the manufacturer's website.
Ensure that the device is properly connected or installed to the computer. If you are using a PC/PCMCIA card, unplug it from the slot and plug it back in. If you have an internal wireless adapter installed, open the computer casing (refer to your computer's manual for instructions). Unplug the card from its slot, wipe the gold pins on the edges with a clean cloth and plug the card back into the slot. Close the computer casing and see if the procedure generates any positive changes.
If the wireless adapter still fails to function even after following these steps, the device may need to be replaced.