Windows 10 Professional and Enterprise include a tool called Bitlocker, which can provide total hard drive encryption for modern TPM based laptops.  The screenshots included provided excellent step-by-step documentation:

If you’re running a Windows 10 Pro or Enterprise laptop then it’s ridiculously simple to encrypt it using BitLocker.  Our laptops contain almost every detail of our lives, much of it information we’d prefer to keep confidential. Not just personal details, but business-critical documents that would be deeply embarrassing to lose. If your laptop gets stolen, you really don’t want the awkward conversation with your boss about what may leak out.

Don’t think the Windows password is enough to protect you either; determined thieves will find a way to bypass that lock screen. Even if you’ve added extra biometric protection via Windows Hello, they can use the brute-force method of removing the hard disk. If you haven’t encrypted it, it’s child’s play to read the data.

7 Step guide using BitLocker — You’ll need to be logged in as an administrator for the steps below to work. Also note that you might want to print off the password (you can save it to an external drive as well), so connecting a printer beforehand is a good idea.