Intel Centrino Wireless-N 100

So my younger brother and my younger sister both received Acer Aspire 5349-2685 laptops for Christmas. Mind you, neither of them are computer enthusiast so the limitations of their hardware don't really phase them.

However, my younger brother's laptop is having trouble maintaining a decent wireless signal while using the Intel Centrino Wireless N 100 while my younger sister's laptop, using the same hardware, is having no issues at all. Even beside the wireless modem he's only receiving between 76%-84% signal strength and if he leaves the room it's in it dramatically drops to 10%-12% and as soon as he walks through the doorway he loses connection. My younger sister on the other hand had walked to our neighbor's house and back, and has been all over the house while never going below 60% signal strength.

We've tried updating the drivers from both Intel's website and Acer's. We've tried letting Windows automatically assign the drivers, and we've even went into the settings on both the laptop and the wireless modem and increased the transmitting power to full and still, nothing. It has made NO difference whatsoever to his signal strength.

Does anyone else have any ideas we could try to boost the signal strength short of disassembling the laptop and checking the hardware/swapping out the hardware?