Have to Keep Unplugging Router

Hi,

I've found similar questions in the forum, but couldn't really find any suggestions that helped.

I've got an HP Desktop running Windows 7, another with Vista in the same room, and an HP laptop running Vista downstairs. Our linksys router is in the basement.

The 7 desktop has no issue with the wireless network, finding or staying connected. However, the two Vista systems will tend to lose their connection to the network, and even though they can still see the network/router, they are unable to connect to it. I have to unplug the router, wait a bit, and plug it back in. Once I do that, they have no problem latching back onto it. The disconnection will tend to occur when they've been idle for a while, but I think it also will happen during normal use.

I've told my wife her magnetic polarity is in opposition to that of her laptop, but she's not buying it anymore.

Any advice? Thx!