One of my favourite apps is Filezilla server. A fully functional free ftp server for Windows. The Filezilla client is multi platform but the server is what I use for Windows platforms as a matter of preference. I had cause to use the Filezilla server in a recent project and it was invaluable in being able to bridge the connection between two machines on different platforms with the Windows server as middle man running the Filezilla server. It takes only a minute to install but I carry it round with me on usb and on a web accessible ftp server (runnning Filezilla of course).
You can get both the client and the server here
The recent update to 0.9.39 was not a major one but I am glad to see the project continues to be maintaned.