Whether you have a home network or are among the ever-increasing number of people signing up for broadband Internet access, your computer’s Network Interface Card is its lifeline to the rest of the world. Making sure your NIC runs at peak performance is a big priority for any PC user, and doing so has become increasingly difficult because of the problems associated with wireless NICs

Most of today’s computers have a NIC integrated directly into the computer’s motherboard. If you have an older computer, the NIC is most likely installed in a Peripheral Component Interconnect (PCI) slot, or it may have an external NIC that attaches to a USB port.

If the computer has a wired NIC, you can identify it by looking for an Ethernet port, which looks like an oversized phone jack and has lights above or below it that flash to indicate network activity. An Ethernet cable attaches to the jack, and then the other end of the cable attaches to a broadband modem or to a router (also called a gateway or access point) if you have a home network. Wireless NICs typically attach to one of the computer’s USB ports (or slide into an expansion bay if you have a notebook computer), although some wireless NICs designed for desktop PCs use a PCI slot and have an antenna instead of an Ethernet port.

The NIC is just one link in the chain between the computer and the Internet or network, so it’s sometimes difficult to tell if the NIC is responsible
when those types of connections go haywire. With wired and wireless NICs, if the connection is working but seems very slow, then the NIC is likely to blame. If there is no connection at all, check the router and broadband modem first to make sure they are plugged in and operational. Wired NICs are incredibly reliable, while wireless NICs are notoriously unreliable, so keep that in mind when determining what is responsible for network and Internet problems.

If the router and broadband modem seem to be working properly and you don’t see any lights blinking on the NIC, the NIC is likely dead and needs to be replaced. Beyond that, there are several common troubleshooting steps you can take that will clear up most problems. All of the following tips apply to Windows XP but will work with other versions of Windows with slight modifications.