I installed Visual Studio 2008 on my Windows 7 x64 laptop together with installation of Service Pack 1.
Now I want to add x64 platform to my C++ solution. But there is no x64 platform available in the configuration manager for my project. I'm sure I manually selected x64 support during the Visual Studio installation and it was installed.
What is wrong with my setup?
If I recall, VS 2008 Pro doesn't install the 64-bit compiler and tools by default. You have to explicitly select them during the installation.
- Control Panel -> Uninstall Programs.
- Select Visual Studio and click Uninstall/Change.
- Wait. Wait some more. Click Next.
- Choose Add or Remove Features.
- Expand MSVC 2008 -> Language Tools -> Visual C++.
- Select X64 Compilers and Tools.
You'll probably need your original installation media.
Once the 64-bit compiler and tools are installed, you should be able to add a 64-bit configuration to your solution.
See "Use Visual Studio to build 64-bit application" for all you need to build x64 apps with Visual Studio 2008.
Visual Studio 2008 only comes with x64 compiler with the Professional editions and higher. You can download the free Windows SDK from MSDN to get the x64 compiler.
If your projects don't have the x64 configuration, just add that configuration via the configuration manager. I don't remember if 2008 created the x64 configuration by default but I suspect not.
I also seem to remember that you can just add the x64 configuration to the solution and it will prompt on whether or not to add it to all of the contained projects but my memory is rusty on that one.
Regardless, once you've got the configurations added, you'll need to modify anything you'd modified before in project settings. Output paths, library dependencies, etc. The New Configuration "Wizard" is pretty dumb.
来源：https://stackoverflow.com/questions/5979675/visual-studio-2008-c-no-x64-platform