After I installed Windows XP SP2, my Dell Inspiron 600m doesn't boot consistently when it is not plugged in. Sometimes it does, and sometimes it doesn't, which is frustrating. Windows XP gets to a certain point (right before the login screen), then I get a hard lock and I have to pull the battery out, reset it, and try again. This doesn't happen when I have it plugged in. HELP!!! Thanks.