Poor link quality or range can be caused by environmental interference, such as lead-based paint and concrete walls. Move the antenna of the Wireless Ndx PCI Adapter or reposition a computer using the PC Card to improve the link quality. If possible, ensure that there are no obstructions between wireless clients and the router.
Perform a wireless site scan or site survey in the client utility for your wireless adapter to check for any adjacent networks. If you find any adjacent networks, check to see what channels the networks are using. Although the router will try to select the best available wireless channel, if your router and another network are running on the same channel, you may need to adjust change your router's settings to use another channel.
Some electronic devices, such as 2.4GHz phones and microwave ovens, may interfere with the wireless signal and affect your wireless range and link quality. Try creating a wireless connection on a different channel.