Wireless Problem

[XxGodJrxX]

My gf's computer is having trouble with her wireless connection at her house. Up until a week ago, things were working fine. Now, she is being kicked off the wireless network and the computer keeps attempting to connect to a neighbor's network. This connection is basically only working for 2 or 3 minutes at a time. The computer does connect to other networks without any problems, like the one in my house for example. I have tried removing the offending network from the list of wireless networks in the advanced tab of the wireless network list, and yet it keeps popping up over and over. I am not sure whether it is that this signal is too weak. Perhaps the neighbor's is stronger than her landlord's network? I have no idea. What am I supposed to do??? Any help would be greatly appreciated. :-)