CCDciel is free software released under the terms of the
GNU General Public License
CCDciel can run on any current version of Windows. It may run on XP but you can experience ASCOM driver crash.
The CCDciel installer always install a 32bit version even in a 64bit Windows system because very few ASCOM driver work with a 64bit application.
To use the devices connected to your Windows computer you need the ASCOM platform and the drivers for you hardware.
But you can also use the devices connected to a remote Linux system (Raspberry PI for example) using the INDI protocol.
You can download the setup installer from the Sourceforge download link.
See also the list of the optional dependencies to install to take full advantage of the software.