Sometimes, shutting down doesn't really mean shutting down.
As with any software, it's important to keep Windows 10 up to date and fully patched, whether you're a business user or a consumer. However, in order for updates to be applied properly, your computers need to be rebooted. Unfortunately, due to a feature of Windows 10, called fast startup, that might not be happening.
Put simply, fast startup is a kind of system shutdown, but like the hibernate function, it saves some information about the current state of your computer. Unlike hibernate, it doesn’t remember what applications or files you had open, but it does save crucial parts of the Windows operating system, and that means when you start up your PC, it’s quicker than a full reboot.
Because fast startup doesn’t fully reboot Windows, updates cannot be applied. The same applies with the hibernate function. If you only ever use fast startup to shut down your PC, Windows won't be properly patched.
There are a few different ways to solve the problem:
If you decide you don’t want do manual restarts or shutdowns, then can disable fast startup relatively easily:
By turning off fast startup, your computer will take a bit longer to start up. However, it’s only a matter of seconds, and if your PC boots from an SSD (solid-state drive), the difference will probably not even be noticeable.