There really aren't any settings you could improve the signal strength with that router. So, you could try the previously mentioned suggestion or, you can buy some High Gain antennas for the router. They're pretty cheap ($15 American) and you should be able to find them in most tech stores...
well you ought to get some signal now, just not very good right? If so the high gain's will help out quite a bit, but if you can't see the network now, probably a 50/50 chance or so, could be something really thick between the two components