Can a Windows or Linux password be brute-forced on a public network?

I am at a hotel that has a public network. I have a Windows machine with a wired connection to it. "Network and Sharing" has network discovery on. No folders are shared except "Users", which is shared by default. Is it possible for someone on the same network to gain the password for an administrator account on a Windows or Linux machine through a brute-force attack? Let's assume that all users' passwords are strong.