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In my office we have four computers on a LAN: Two Ubuntu machines and two Vistas. Each is on its own power strip with surge protection, no UPS. The ADSL router is on a separate outlet. When we come in in the morning, before turning on the lights, it can be seen that the router has power, as do all four of the power strips. The computers can all be powered on without turning on the lights, and they have internet connection so I know that the router is powered on even before turning on the lights.

If one turns on the lights before booting any of the computers, then one of the Vista machines boots up when the lights come on. It will stay up even if the lights are then turned off. Thinking that maybe something is sending wake-on-lan I unplugged the network cable and tried again, sure enough the possessed Vista machine boot right up when the lights come on.

What might cause this? Should I document everything in a video to post to youtube to prove that the power strips are in fact powered even when the lights are off?

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Please mention the configuration of that Vista PC, along with its motherboard model and BIOS version. Also please let me know if your using any daylight saving sensors or power management profiles. Then I should be able to help you cure the possessed PC with the devil inside.. –  aliasgar Jan 25 '13 at 7:00
    
usb light sensor plugged into the weirdo box? –  Dan-o Jan 25 '13 at 7:49
    
Thanks. There are no unusual sensors installed on the machine. It is a Fujistu Esprimo P1500 that we were unable to install Ubuntu on due to ACPI issues with the motherboard. Whoever made that motherboard didn't see fit to put their brand name on it in any location that I was able to find, but if it is critical then I could start probing Vista for the information. –  dotancohen Jan 25 '13 at 8:01
    
I'm not actually interested in curing it, but I am curious as to what signal is breaching a hypothetical envelope surrounding the machine. I've eliminated every tangible object but the power cord by method of disconnect, and I've eliminated the power cord by method of "it is already energized, and the machine stays on when the lights go back off". –  dotancohen Jan 25 '13 at 8:09
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1 Answer

It can be an issue of the power supply being faulty and sending false power on signals when its power gets disturbed.

Is your computer turned off, or just hibernated? There was a similar issue mentioned here:

A program can tell Vista wait a certain period of time and then invoke some executable code at an address the program provides. An example is if you use a program like Microsoft's Outlook email client where you can set a reminder task for a future date and time. Outlook tells Vista to wait X amount of time and then execute some Outlook code. That Outlook code then displays your reminder.

But what happens if you put your computer to sleep or into hibernation? Well, before Vista you wouldn't get your reminder. Or maybe your anti-virus scan wouldn't happen. Or maybe Windows Update wouldn't run. Vista changed all that.

When Vista goes to sleep or into hibernation it first checks to see if there are any timers set to go off. If there is, it takes the next timer set to go off and sets an alarm in the platform hardware for that day and time. In the hardware this is typically an alarm that's part of the real time clock (RTC). Once Vista sets the RTC alarm it goes to sleep or into hibernation.

When the RTC alarm goes off your system turns on. Vista resumes and is notified of the alarm having gone off. Vista checks its timer list and executes the code associated with the timer that when off. When the code is done executing Vista will go back to sleep after two minutes of idle time.

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It is in fact hibernated, and the secretary does use outlook (but only for email, there is no way that see even knows what the reminders are). I'll try to power it down and see. –  dotancohen Jan 25 '13 at 8:10
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You are right, it only starts up automatically when hibernated. –  dotancohen Jan 25 '13 at 8:32
    
@dotancohen Well, then the solution is either turning off all wakeup alarms as stated in the link (which might not be the most desired of features if you want the computer to wake up for certain alarms), or turning the computers off. –  ThePiachu Jan 25 '13 at 8:43
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@dotancohen Are you turning a lot of lights with one switch? Are they fluorescent lamps? In that case it might create a small power surge that could affect the power supply. Fluorescent lamps require some charge build-up at the start, which could affect other devices connected to the same power source. –  ThePiachu Jan 25 '13 at 11:07
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Yes, they are 9 fluorescent bulbs being lit when the switch is flipped. Perhaps some "wake after power failure" thing is being activated by the sudden change in line voltage when the lights go on. –  dotancohen Jan 25 '13 at 11:23
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