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My UPS has outlets labelled "Master" and "Controlled by Master". The computer's power supply is plugged into the "Master", and a power strip feeding a bunch of other things is plugged into the "Controlled by Master" outlet. This outlet turns off when the computer is turned off. At least, it is supposed to do so, and for the previous eight years it did just that.

The new computer does not turn off that outlet when it is shut down. So now, when I turn off the computer, my scanner, my monitor, my desk lamp, my sound system, and my USB hubs all stay powered up.

I have gone so far as to turn off the switch on the power supply and even unplug the computer, but the UPS continues to feed power to the half dozen or so accessories that are connected to the "Controlled by Master" outlet, along with the dozen or so items connected through the USB hubs.

Although the USB hubs are powered by the UPS, I think the hubs may be a similar but separate issue. When the computer was at the computer shop without benefit of the UPS, there was no way to power down the USB ports short of unplugging the computer from the wall.

I don't know by what mechanism the UPS "knows" when the computer shuts down, possibly something that senses current draw. My guess is that the problem is either with the UPS itself (unlikely, it was working properly with the old computer); with the new computer hardware (is it still drawing current even when shut down?); or does the UPS rely not on current draw but from some signal that is missing from the Windows 8.1 operating system?
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