The game was not available for buying for quite some time. In the meantime however, it is available via GOG. It got re-released on 9th of September 2021, to honor the occasion of 55 years of Star Trek.
On Windows 10 it is know to happen, that the CD installer gets stuck right after starting it. It is however not necessary to actually use the installer. You can simply copy the contents from the folder Setup over into a folder on your hard drive and start Star Trek.exe from there. Starting it directly from the CD won't work as the CD/Image is read-only. The game notices this and stops with a corresponding notification message.