"Windows System Programming" is clearly written, with subjects presented in a logical order. The program examples tie the topics together so that you can see how the Windows API functions work in real Windows application programs. This is not an internals book; it explains the core Windows API, and the author clearly defines the book's scope.
The subject matter is very important in a lot of practical application development situations where the GUI is not an issue (this is the code "under" the GUI that does the real work). I was able to adapt two of the example programs ("JobShell" from the Process Mgt chapter and "Pipe" from the Interprocess Comm chapter) for use in a recent consulting job. Everything worked well and the changes for my particular task were easy to do, but I would not have been able to figure it out myself without spending a lot of time. I'm thinking of adapting one of the thread synchronization examples in an upcoming assignment. I looked at other books, and none of them had anything even close to these very useful examples.
By the way, the example code (download it from the URL given in the book) is clear, quite reliable (maybe it's not perfect for all I know, but what code is?), and it performs extensive error checking. The code listed in the text is usually streamlined so that the reader can see the logic without getting bogged down in error checking details (the author explains this in the text). I disagree with the March 28 reviewer about this, but maybe he was only looking at the code in the text. The code is clear, straight-forward, seldom "tricky" in any way, generally well documented, and the author goes to a lot of trouble to point out variations, other methods to solve the same problem, performance tradeoffs, and other useful and thought-provoking information. Incidentally, the coding style is compatible with professionally developed Windows code I've encountered during consulting projects.
Finally, the author maintains a web site (same as the code download URL) with corrections, updates, and a lot of additional information that is informative, helpful, and sometimes entertaining and even witty. He also responded quickly when I sent an email requesting some clarification.
So, Hart gets 5 stars for this book; it really helped me in "real world" situations. I wish more authors would write as well, take as much effort with their examples, and support their books the way this author does.