Jared writes "Microsoft says it is investigating reports of notebooks with poor battery life with Windows 7, as first reported by users on Microsoft TechNet. These users claim their batteries were working just fine under Windows XP and/or Windows Vista, and others are saying that battery problems occur on their new Windows 7 PCs. Under Win7, certain machines spit out the following warning message: 'Consider replacing your battery. There is a problem with your battery, so your computer might shut down suddenly.' The warning is normally issued after using the computer's BIOS to determine whether a battery needs replacement, but in this case it appears the operating system and not the battery is the problem. These customers say their PC's battery life is noticeably lower, with some going as far as to say that it has become completely unusable after a few weeks. To make matters worse, others are reporting that downgrading to an earlier version of Windows doesn't fix the problem."