While upgrading to Windows 7, something went wrong and one of the things I noticed was that the battery was no longer being detected. I eventually reinstalled Vista from the CD's that came with the laptop, but the "battery not detected" message is still there. I have now successfully installed Windows 7, and still the same. The computer seems to work if it is on and I unplug AC, but will not start from battery. Any ideas how to solve this problem?