Do you expect the signal strength to be poor where you are, or might it be something mechanical, like an antenna disconnected inside the laptop?
Is the router/WAP yours? Have you tried adding a simple reflector to it? That changed my preferred laptop location from marginal to solid, with no change in the laptop.
EZ-12, printed on photo paper for thick stock, with aluminum foil glued to the sail, provides a substantial boost in signal.
The netstumbler trace. Make the tabs longer than the template drawing, for easier assembly.