If you've ever taken your laptop to a public place and turned it on, your personal name is visible while you are logging in.  Not a big deal, but if you're concerned that someone would spot your name, then here's the solution to change your name on the Windows login screen.

Be aware that once you change it, it will change on all of your Microsoft products and web sites. Microsoft Office, Xbox.com (won't change your Gamertag) or any sites you use Microsoft logins.