Lots of home equipment which use radio can affect a wireless router connection. These can include cordless phones, baby alarms or even door bells. Proximity of the router or PC to TVs, stereos, speakers or even microwave ovens can degrade the connection. Often changing the wireless channel on the homehub will resolve the problem. May take a bit of experimentation with different chanels though.
To access the BT Homehub manager just open a web browser on the PC and enter 192.168.1.254 into the address bar and press enter. As there are 3 different versions of the homehub the method of changing channels varies. Info available on bt.com/help. Look in the broadband section. Or check out the BT custhelp YouTube videos at
YouTube - BTCare's Channel which show you how.