FileZilla is the de facto Windows FTP server solution. It is an open-source, free application distributed under the GNU public licence.
Installation is fairly straightforward, simply download and run the installer binary. Be careful, though, because Sourceforge sneaks some “sponsored software” into the installer, and you may end up with a little bloatware that you didn’t want or need. The default settings are fine, but you may want to change the default port if you’re going to be opening this sucker to the entire Interweb. Today, though, we’re staying behind the safety of our hardware firewall, so we can only access files if we’re connected to the same wifi.
Setup is a little convoluted, but can be made simple by following these easy steps:
One the server daemon is running and you are in the main window, click the “Users” button to add users to the server.
In the Users window, click the “Add” button on the right side, type in a username and click “OK”. The user you just specified will be enabled automatically. You can assign a password for this user by checking the box next to “Password” and typing one in.
Clicking the “Shared Folders” branch (on the left side), you can add directories and assign permissions. I only assign write, delete, and append permissions to my admin account while I give other users the ability to read files on the server. Each directory will require an alias, so give it something easy to remember when you open it in your FTP client.