From a marketing point of view, it’s an obvious message for Dixons to be pushing. But in reality, as we all know, one of the great merits of Windows 7 is that most of us don’t need a new PC to run it. I use it happily on an old Advent laptop with 1GB of RAM and a Pentium Dual-Core processor; David Bayon runs it on his Atom-powered Samsung NC10 netbook. If there was ever an edition of Windows that didn’t mean “time for a new PC”, this is it.

With Microsoft getting so much right in Windows 7, it’s a disappointment to see it permitting (perhaps even supporting) such a misleading marketing slogan. And I think it’s a mistake. In the coming years Windows is going to be increasingly threatened from multiple directions — by a buoyant Apple, by emergent operating systems such as Chrome OS and by cloud-based mobile computing. Surely as the battle grows Microsoft will want its best foot forward, in the shape of a satisfied user base. The last thing it will want is to be weighed down by still-lingering resentments over Vista.

Yet this slogan seems designed to deliver precisely that outcome. Dissatisfied customers won’t appreciate being told they must write off their old PC to escape their unsatisfactory OS. Many who can’t afford a new PC will stick with Vista and remain disgruntled with it. And those who know the truth – that any machine that runs Vista will run Windows 7 better – will resent Microsoft’s apparent collusion in an attempt to get them to waste money on an unnecessary new PC.