USB wireless adapter does not switch off after PC powers off

[Randominal]

So i have a USB netgear wireless adapter but the thing is wen i switch off my computer the blue light stays on and does not switch off unless i unplug it and then plug it back in again.
I also have a USB mouse but that does not stay switched on.
So why is this the case and how can i stop it cos its a pain having to unplug it every time i switch off my PC

 

[RoBo]

I don't think there is anything you can do.

Why do you want it switched off? It's using very very very very little power.