Free, simple yet robust and reliable SSH(2) and SFTP Server for Windows. It features 3 authentication types (including public-key auth with multiple keys per user) as well as a good SFTP subsystem and channel forwarding.
And it has some nice security features such as a forced delay upon new connection (useful to defeat brute-force attacks) and a handy "tarpit" to ban attackers´ IPs.
Also, it fully supports virtual folders with per-folder security. And its remote management console allows you to manage SilverSHielD from anywhere.
Furthermore, you can use the Command-Line Interface (CLI) to remotely configure your SilverSHielD server and integrate its management into 3rd party management tools.
Note: It´s free of charge if 3 simultaneous connections from a single client is sufficient for you and if you don´t use it for commercial purposes.
System Requirements: Windows 2000/XP/2003/Vista/2008/7 (x86/x64)
Operating System Support: Windows 7, Windows Vista, Windows XP, Other