At first you should make sure that the Visual Studio edition you are using allows building 64-bit code. If you want to develop 64-bit applications using the latest (at the moment of writing this course) Visual Studio 2008 version, here is a table that will help you understand what Visual Studio edition you need.

1. Lesson 4. Creating the 64-bit
configuration
Compiler
At first you should make sure that the Visual Studio edition you are using allows building 64-bit code. If
you want to develop 64-bit applications using the latest (at the moment of writing this course) Visual
Studio 2008 version, here is a table that will help you understand what Visual Studio edition you need.
Table 1 - Capabilities of different Visual Studio 2008 editions
If the Visual Studio edition you are using allows creating 64-bit code, you should check if the 64-bit
compiler is installed. Figure 1 shows the page of installing Visual Studio 2008 components where
installation of the 64-bit compiler is disabled.

2. Figure 1 - The 64-bit compiler is disabled when installing Visual Studio 2008
Creating the 64-bit configuration
Creating the 64-bit version of a project in Visual Studio 2005/2008 is a rather simple procedure.
Difficulties will appear later at the step of building the new configuration and searching for errors in it.
To create a 64-bit configuration you should make the following 4 steps:
Step 1
Open the configuration manager as shown in Figure 2:
Figure 2 - Launching the configuration manager
Step 2
Choose support of the new platform in the configuration manager (Figure 3):
Figure 3 - Creating a new configuration
Step 3
Choose the 64-bit platform (x64) and take the 32-bit version settings as the base (Figure 4). Visual Studio
environment will automatically modify those settings that impact the build mode.

3. Figure 4 - Choosing x64 as the platform and loading the Win32 configuration as the base
Step 4
You have added the new configuration and now may select the 64-bit configuration version and start
compiling the 64-bit application. Figure 5 shows how to choose the 64-bit building configuration.
Figure 5 - Now you have both the 32-bit and 64-bit configurations
Modifying parameters
If you are lucky, you will not have to adjust the 64-bit project. But this depends upon the project, its
complexity and the number of libraries being used. The only thing you should modify right away is the
stack size. If your project uses the stack of the default size, i.e. 1 Mbyte, you should change it to 2-3
Mbytes for the 64-bit version. It is not necessary but it is better to secure yourself from possible issues
beforehand. If you use the stack of a size different from that by default, you should make it twice-thrice
larger for the 64-bit version. To do it find and change the parameters Stack Reserve Size and Stack
Commit Size in the project settings (see Figure 6).

4. Figure 6 - Location of project settings defining the stack size
What next?
Having the 64-bit configuration of a project does not mean that it will compile well and work at all. The
process of compilation and detection of hidden errors will be discussed in the next lessons.
The course authors: Andrey Karpov (karpov@viva64.com), Evgeniy Ryzhkov (evg@viva64.com).
The rightholder of the course "Lessons on development of 64-bit C/C++ applications" is OOO "Program
Verification Systems". The company develops software in the sphere of source program code analysis.
The company's site: http://www.viva64.com.
Contacts: e-mail: support@viva64.com, Tula, 300027, PO box 1800.