Training. It includes dozens of different engines and "tutors" that explain why your move was a mistake.
If you are looking for the original MS-DOS classic, it is now considered . Grandmaster Chess Free Download
Many "free game" sites bundle downloads with adware or trojans. Training
Modern Windows systems cannot run this natively. You will need DOSBox (an emulator) to play it. I need to know your goal:
To give you the most "useful" download link or setup guide, I need to know your goal: