unable to connect wirelessly - windows 7 and new acer laptop

i apologise if this seems like a stupid post. i am trying to sort out my new acer laptop (windows 7 home premium) but have a problem with wireless connections. if i am next to the wireless modem then my connection is fine, but as soon as i move more than 4 m away i lose the connection although sometimes it claims to still be able to 'see' the network. this happened with the last modem i had as well. i also have an xp desktop, an HTC phone (runs android) and a mac all of which can connect to this wireless network throughout my house without a problem and have always been able to do so. the wireless signal is strong everywhere i want to use it. It is just a problem with the windows 7 laptop, which as i said works fine next to the modem and also fine via ethernet cable.
i presume there must be a setting on the acer that needs to be changed?

thanks for any help

Simon

ps
all drivers are up to date

 

thanks. windows is managing the wifi adaptor, power management checked. access point channel is 1 at present. mostly the laptop claims not to be able to see the network and suggests i am not in range, other times it suggest no network access under both IPv$ and IPv6 connectivity
any advice is appreciated

 

thank you sorry to be so challenging. ip6 removed but no better.
when i remove the back of the laptop there is only one component that has 2 wires going to it and they are both connected.

thanks