Windows 7 USB power lose after a few seconds / minutes

My friend's computer has a problem where the USB ports causes problems with the power of some devices connected to the computer.

The USB mouse has no problems, however the Wireless Adapter looses power after around 20 seconds of use and USB Flash Drives cause the computer to either freeze, lose power (and become unresponsive) or become disconnected (still shown in Device Manager, but not in My Computer) when trying to transfer any type of file to / from the computer.

I have a suspicion it's the Motherboard but could it also be a Software problem? Tried a new case, RAM, CPU and GFX Card which had no effect.

The problem occurs on both the Front USB and Back (Motherboard) USB Ports.

UPDATE: Tried the USB devices with an Ubuntu Live CD and they work fine, could this mean it's a problem with Windows (x64)?

Solution 1:

The solution was to disable "Allow this computer to turn off this device to safe power" on both the Wireless adapter and all USB Root Hubs showing in "Device Manager".