CHECK YOUR WIRELESS NETWORK FOR HACKERS

You can download this free program, which has not been updated for VISTA.

NETWORK STUMBLER Version 0.4.0 (April 21, 2004)

The program installed well on my laptop, and ran with no problems. I used XP professional.
It also shows a graph which displays the noise/signal ratio of your signal, and other signals.

In a semi-detached house, hackers are less of a problem, you do not want more than a weak signal. And you will want the signal sent more from the centre of the house. If a hacker is using a program to hack your system, there is no point using WEP, because he will be able to crack it anyway.

It may not support all wireless cards, but it is free and tells you if anybody is using your access point, see bottom and it tells the number of AP's connected.

you can download it from PC WORLD:

HERE

http://www.pcworld.com/downloads/file/
fid,23439-order,1-page,1-c,alldownloads/description.html?findid=51212

Or you can download from the offical site:

HERE

http://www.netstumbler.com/downloads/