Well said.

Are you in an apartment or condo, where others live above, below or to the side of you? If yes, their phones, routers, microwave ovens etc. can also cause interference.

I'd also suggest investigate all other possibilities, (e.g., does it work OK five feet from the router?, 10 feet, etc?) locations of metal shelving, router firmware, channels, etc. before adding more hardware.

Also, in the previous post I was not referring to the laptop battery/ac power settings, but to the WiFi card's device/driver settings. But, sometimes these WiFi card settings are coupled with the laptop power scheme settings, such as 'when on battery, enable Power Save Mode for wireless radio'.

One more idea to help troubleshoot. WiFi card device drivers tyically -- but not always, look at manufacturers website for utilities -- have some way to monitor the status of the card, such as a graphical signal strength meter, or a power level setting, etc.