Windows 10: Power supply running power when I shut down?

I have a Corsair CX750M PSU.. These units remain on even after shutting down my system so, should I flip the switch off when I'm not using it or, is it safe to leave that switch on? Thanks!

:)

 

How do I stop a windows update, if there is a power outage and I'm on an uninterruptible power supply?

I've read too much about people having problems with their PCs after it shut down unexpectedly during a power outage. So I decided to buy an Uninterruptible Power Supply (UPS).

From the product reviews of the UPS model I bought, most people were saying that they had enough time to save their work and shut down. However, I imagine that if a power outage were to happen during a windows update, is there any way to stop the windows
update so I can shut down the computer?

The UPS I bought is a CyberPower Ecologic Series EC750G, with 450 W. My desktop PC's power supply unit is also rated at 450 W.

 

Power supply getting OFF while putting the PC on Sleep mode.

Original Title : My PC's power supply turns off then back on when I put it to sleep

Hi. For some reason when I put my PC to sleep it's power supply turns off then turns back on. So afterwards I have to press the power button and wait for it to start up like it would if I were to shut it down. Everything starts up normally. This problem
started today. The power supply I'm using is the Evga 430w 80+ certified PSU.