Bitvise provides SSH server software for Microsoft Windows systems. If you are looking for free SSH server software, the software is free for personal use. The Bitvise SSH Server License Terms page states:
Personal Use. No activation code is required for non-commercial personal use. Simply download the latest Bitvise SSH Server version, make sure that you have no pre-existing installations, and select 'Personal Edition' when offered the choice during installation. Note, however, that you may not use Bitvise SSH Server in personal mode unless your use is both personal and non-commercial. All organizations must purchase licenses.
Note: the installation instructions below are for the installation of Bitvise SSH Server version 6.47 on a Microsoft Windows 10 system, but should be applicable to other versions as well.
After downloading the software, when you start the installation, you will be asked to agree to the End User License Agreement. You can change the installation location from the default location at this point, if you wish.
At the next screen you can select from the standard or personal edition. For the personal edition, usage is free and never expires, but is limited to non-commercial personal use. The personal edition has the following limitations compared to the standard edition:
If you select the personal edition, you will be prompted to provide your first, middle, and last name.
Once you provide a name, you should see the "installation completed" window.
When you click on OK, the Bitvise SSH Server Control Panel will open. You should reboot the system. If you open a command prompt window, you can verify the system is now listening on the standard SSH port, port 22, if you wish.
C:\Users\nell>netstat -an | find "22" | find "LISTENING" TCP 0.0.0.0:22 0.0.0.0:0 LISTENING TCP 192.168.0.3:22184 0.0.0.0:0 LISTENING TCP [::]:22 [::]:0 LISTENING C:\Users\nell>
The 0.0.0.0:22 above indicates that the system is listening
on all network interfaces on port 22 for the
IPv4 protocol.
By default, the SSH server service will be enabled on the "domain" and "private" network profiles, but if you would like to be able to connect to the system via SSH when it is connected to any network, you can take the steps listed at Modifying an existing Windows Firewall rule.
Other free SSH server programs for Microsoft Windows systems are listed in the following articles:
Copssh 5.0.1
freeSSHd on Windows 8
PowerShell SSH Server
for Windows
SilverSHielD SSH
Server for Windows