And now several days later I say: "What worries?" Win7 is running like a dream on my lappy and while I clung to XP for ages because I didn't want to switch to Vista, I'm now of the opinion that XP is now old and busted - to coin one of my favourite Kris_Bism's.
Yeah Bob I know the hosts file and checked it when I was troubleshooting but I realised early on it wasn't a DNS issue. It was something weirder... Cheers tho.