Poblem solved. My IT guys from work installed me one of these in the end which I'm using as a repeater.
http://www.draytek.co.uk/products/ap800.htmlNow I get 5 bars wifi up stairs no problem
Only downside is the download speed is a bit comprimised when using the laptop upstairs. i.e.
Desktop pc connected to infinity via ethermet = 38mbs
Laptop connected to wifi Homehub3 = 20mbs
Laptop connected to wifi Homehub3 then Draytek repeater = 8mbs (so thats a 30mbs drop which is a shame)
However all works well so no complaints. My IT guys have email Draytek to ask the question is this drop in download speed normal or is there a setting that needs to be changed etc.