Responding to complaints that have surfaced on the company’s support forums, Microsoft said this week that it was investing laptop battery issues that are allegedly caused by Windows 7. The problem was first reported in mid-2009, before Windows 7 shipped.

"We are investigating this issue in conjunction with our hardware partners," a Microsoft statement reads. "The warning received in Windows 7 uses firmware information to determine if battery replacement is needed. We are working with our partners to determine the root cause and will update with information and guidance as it becomes available."

According to the complaints, some laptops running Windows XP or Windows Vista suddenly exhibited much poorer battery life once upgraded or migrated to Windows 7 than usual. Some people also claim that the battery life issue is irreversible, stating: Once it happens, even reverting to Windows XP or Windows Vista does not fix the issues.

However, Microsoft says it is most likely a software issue: it suspects that the part of Windows 7 that probes the system for battery life is simply misfiring and causing the system to believe that is running out of battery life much earlier than is really the case.

While looking through the forum, it appears that the problems affect a wide range of notebooks from companies such as Acer, Dell, HP, Samsung, Sony and Toshiba.