I have a new laptop with Windows 7 professional installed, and a 2 year old Desktop which I installed Windows 7 professional about 2 months ago. Both machines work fine.
Any hardware that is plugged into a USB port work fine, but when trying to disconnect with the mouse, a box comes up in the bottom right-hand corner of the screen saying: "Ok to disconnect (and whatever the hardware is)". So far so good. Unfortunately the USB external hardware remains powered via the USB. Also, sometimes a box appears in the middle of the screen saying that the usb is busy at the moment and to try later. No amount of waiting give a result.