Help with wireless router!

An ExtremeTech reader writes in for help with their wireless router. Apparently once the laptop is connected, their desktop has no Internet access whatsoever! The advice they received matchs what I would have recommended in my column featured in IT Professionals, Just ask Matt.

Here is the problem. After setting up the router following the instructions in the manual I can access the internet just fine through my desktop BUT only when the WLAN adapter in the laptop is off. As soon as I plug it in WinXPpro establishes a “wireless connection” and the indicators on the adapter, router, AND cable modem all show data going through full speed! From that moment I cannot do anything from my desktop, even access the router setup. I cannot access anything from my laptop either. When I doubleclick on the established connection it shows packets and packets of data being sent and just a few received. If I unplug the WLAN adapter or turn off the laptop, the desktop is back to normal.