It will scan your computer and tell exactly how many drivers - and Windows updates - are missing. It will then allow you to download the missing ones, but in order to do this, you'll need to register. This is free and only takes a bare miniute or two, but users who were accustomed to unencumbered use before might baulk.
This app also offers you a back-up and restore function, which will be essential if you notice any problems after updating - or if you want to make a copy of your drivers when you format your PC, for example. There is also a driver uninstall facility.
