Start > Control Panel > Network and Sharing > Manage Wireless Networks
Scroll down to the name of the network you want. *Make sure it's a different name than the neighbor's(!)
Select the network and move it up on the list using the blue 'up' arrow so windows chooses that one first over the neighbor's.
You can try one more additional step. Right-click on the network on the above list and select 'properties'. Now check the box that says 'connect automatically when this network is in range'. Then hit 'OK'.
A friend is running Vista on their laptop. They have their home network setup as the default which uses a fairly new Netgear router. Each morning when they boot up their system, it automatically connects to a neighbor's network. When they look at the list of available networks, theirs shows a stronger signal than their neighbors. They said that they deleted the neighbor's network from the list of available networks but the next time they boot up, it connects again to that other network.
Any suggestions would be appreciated.