Hi, I have a Gateway AJ2 that is acting up. If I have the battery installed, the computer runs on the battery, regardless if the AC adapter is plugged in or not. If the battery isn't installed, the computer runs on AC with no problems. The battery does not charge. The computer is a little over a year old. I don't exactly recall when the problem started, but it might have been after a Windows Vista update or a bios update. Thanks in advance for any assistance.