When an employee gets up to get a coffee, he leaves his PC behind unlocked, open for anyone who is in the building. Everyone occasionally forgets to lock their PC, but hackers can install malware with a simple USB stick via an employee's account.
Windows 10 has a remedy for this. You can use Bluetooth to pair your PC with another personal device (for example, a smartphone or smartwatch). This way, your PC can detect when you step away and will lock automatically.
Nobody leaves their smartphone behind unattended, do they? A smartwatch is even better. Nobody can get into the PC unnoticed to install malware.