Running XP, and chrome at work, sat on a Dark Fibre running at 1Gbps to our own BGP internet service, with multiple up-streams and LINX peering, so I can test based without involving ISP infrastructure. (we supply similar bandwidth to O2)
And at home I have a Vista 64 bit PC which runs chrome or a netbook running XP and Chrome on Virgin Media 10Mb cable.
Out of interest who do you host the server with, then I can look into who they use as there up-stream providers.