When you log off/shut down does the screen hang at the "Shutting Down" stage or does the screen go black but the fans etc continue to run.
Please fully answer the above question, as the information may help to determine if this is a Windows/software problem or a power/hardware problem.
What type of other USB devices cannot be read, you have said "It works with keyboards, mice and thumb drives." and thumb drives are the only one of the 3 devices that contain data that can be read, the common factor with the three items is that they have very low power requirements, unlike other USB devices such as external CD/DVD drives and HDDs etc.
You said that you thought the computer was freaking out after a driver update, starting Windows in Safe Mode only installs the bare minimum of Windows generic drivers and so if a third party driver is causing the issue it will not happen in Safe Mode as the rogue driver will not have been installed.
There is no need to quote my replies btw