Vista, Hibernate and Windows Update

My laptop lives a boring life. Every morning, I check news and e-mail before going to work. Then I put the machine in hibernate, just to be able to switch it on in half a minute. Maybe I'll go online while watching tv in the evening, and then it's back to hibernate. But in the middle of the night, my laptop lives it's own life. I started suspected something when I woke up to an empty battery every day. Strange. Annoying.

I found the problem after some days, when not hibernating, the battery was happy. But what was happening? As far as I know, hibernate means putting the machine in a power-off state - but saving the contents of RAM, enabling us to start from where we left off when we resume. Turns out this can't be quite true. Cause every night at 01:00 AM my computer would turn itself on - because I'd set Vista to check for automatic updates at that time.

I wasn't quite sure if this was real or not until today, when my colleague Petter showed up at work, telling me had discovered the same thing. His laptop woke him up at 4AM to get the newest updates.

So if you're having mysterious battery-trouble with a laptop running Vista - check your update settings.