Turning USB socket power off and on

In theory powered USB sockets (maybe USB2 and later) can control the power if the hardware supports it.

I don't know if my H/W supports this function, but that's a mute point as I've never found any S/W that implements such control. Has Windows7 made any advance over XP in this arena?

This issue comes up once a year, at about this time, as I have USB powered desk Christmas Tree. OK, it has a switch on the bottom, but I'd really like to be able to control it with an application if possible.
The tree sits on my windowsill, and it's not easy to reach over my monitors. And yes, if this is the worst of my problems, I'm obviously doing OK. :)

Hello Swiftie. Welcome to the forum.

What a wonderful, weird problem. I love it!
So, a USB Christmas tree. What does it do? Can you control it, do a light show to music?

Does the "New Device" icon appear in the Taskbar when this thing is plugged in?
If you go to Devices & Printers, does it show up there?

TVeblen said:

a USB Christmas tree. What does it do? Can you control it, do a light show to music?

As far as the PC is concerned, the tree is completely inert; it draws power, but nothing else.

So, when the tree is on, its' internal electronics runs through a fixed sequence of lights.

Perhaps newer USB Christmas trees appear as a device to the system, and could be controlled. I'll have to look for one of those. My USB aquarium allows control of the speed at which the fish swim, so some of these inexpensive novelty devices have controls!

You could go into the Power Options and see what happens if you toggle the Selective Suspend settings.
Start > Control Panel > Power Options > Change Plan Settings > Change Advanced Power Settings > USB Settings > USB Selective Suspend Setting

This article here shows some promise:
How to Make Your USB Devices Power Down on Safe Removal in Windows - How-To Geek
But without an actual device detected that you could Safely Remove I'm not sure how it would work for your situation.

That was always the problem I ran into - the tree does not manifest itself as a device. I was hoping for some way to turn the power off to a specific USB port. I suspect my easiest option is to use a short USB extension lead, so I can unplug it easily (the USB ports are out of reach from where I sit).