The course is devoted to creation of 64-bit applications in C/C++ language and is intended for the Windows application developers who use Visual Studio 2005/2008/2010 environment. Developers working with other 64-bit operating systems will learn much interesting as well. The course will consider all the steps of creating a new safe 64-bit application or migrating the existing 32-bit code to a 64-bit system. The course is composed of 28 lessons devoted to introduction to 64-bit systems, issues of building 64-bit applications, methods of searching errors specific to 64-bit code and code optimization. Such questions are also considered as estimate of the cost of moving to 64-bit systems and rationality of this move. The contents of the course: Lesson 01. What 64-bit systems are. Lesson 02. Support of 32-bit applications. Lesson 03. Porting code to 64-bit systems. The pros and cons. Lesson 04. Creating the 64-bit configuration. Lesson 05. Building a 64-bit application. Lesson 06. Errors in 64-bit code. Lesson 07. The issues of detecting 64-bit errors. Lesson 08. Static analysis for detecting 64-bit errors. Lesson 09. Pattern 01. Magic numbers. Lesson 10. Pattern 02. Functions with variable number of arguments. Lesson 11. Pattern 03. Shift operations. Lesson 12. Pattern 04. Virtual functions. Lesson 13. Pattern 05. Address arithmetic. Lesson 14. Pattern 06. Changing an array's type. Lesson 15. Pattern 07. Pointer packing. Lesson 16. Pattern 08. Memsize-types in unions. Lesson 17. Pattern 09. Mixed arithmetic. Lesson 18. Pattern 10. Storage of integer values in double. Lesson 19. Pattern 11. Serialization and data interchange. Lesson 20. Pattern 12. Exceptions. Lesson 21. Pattern 13. Data alignment. Lesson 22. Pattern 14. Overloaded functions. Lesson 23. Pattern 15. Growth of structures' sizes. Lesson 24. Phantom errors. Lesson 25. Working with patterns of 64-bit errors in practice. Lesson 26. Optimization of 64-bit programs. Lesson 27. Peculiarities of creating installers for a 64-bit environment. Lesson 28. Estimating the cost of 64-bit migration of C/C++ applications.