I have an Acer Aspire 5542 purchased December 2009 and in the last few months have had problems with battery charging. I get error messages saying "Plugged in not charging" or "Plugged in charging" but the battery indicator does not move except for a few seconds when I first switch on. I have just purchased a replacement battery but the problem remains. I have seen suggestions that I might need to upgrade my BIOS to fix this, if so how do I do that. Any other help would be appreciated. Acer premium helpline tell me I can update the BIOs which is currently Phoenix v. 1.03 but it would be at my own risk! Three possible Bios upgrades are suggested on the Acer website.