Laptop users are complaining that upgrading their OS to Windows 7 is causing all sorts of power management problems.
Some forum posters are complaining that batteries which happily chugged away for hours under XP or even Vista are giving up the game after just minutes in some cases.
Windows 7 informs unfortunate laptop owners that their batteries are dead and need to be replaced with the warning: "Consider replacing your battery. There is a problem with your battery, so your computer might shut down suddenly".
But with some replacements running at up to £150, there is obvious resistance.
And this is not a new problem. The reports started way back in June 2009, when W7 was still at the release candidate stage.
The problem is evidently worse on eldery laptops, which probably explains Microsoft's reluctance to fix it.