ChessRally is a very complete chess game for Windows. It supports both single-player and multi-player games. The game can run on most Windows versions, even Windows 7. However, it won't work on virtualized environments. It has a very clean interface with a well designed board and shiny chess pieces.
Let me first start with what is common for both single- and multiplayer modes. The application can be customized with different themes that already come with the installation file. There is a list of moves that you can check at any time during a match and the rulebook is based on the most widely accepted international rules.
The single player mode allows you to use the computer as a real-time, on-site chess teacher. You can ask it to suggest moves at any time. There is a risk assessment tool that tells you if one of your moves is too risky and can provide suggestions based on that. You can always undo your movements if you find yourself at risk. The Experimenting mode allows you to mess around with certain scenarios in-game to learn to anticipate your opponent's moves. Most of these features are aimed at using the game to teach you how to become a better player. Gladly, they can all be disabled.
Where ChessRally really is big is in multiplayer. You can play against friends both in real-time and via correspondence games. The latter allows you to send your moves via e-mail to your opponents. You can play on more than one board at a time and there are quite a few servers for you to find a game on. You get a ranking based on your skills, so you can find opponents that are on your same level easier.
All in all, ChessRally has many features that go beyond the basic game of chess. It is a great game to play just for fun or to become better at it. And it is beautifully crafted.