C# - How to get Program Files (x86) on Windows 64 bit

The function below will return the x86 Program Files directory in all of these three Windows configurations:

• 32 bit Windows
• 32 bit program running on 64 bit Windows
• 64 bit program running on 64 bit windows

static string ProgramFilesx86()
{
    if( 8 == IntPtr.Size 
        || (!String.IsNullOrEmpty(Environment.GetEnvironmentVariable("PROCESSOR_ARCHITEW6432"))))
    {
        return Environment.GetEnvironmentVariable("ProgramFiles(x86)");
    }

    return Environment.GetEnvironmentVariable("ProgramFiles");
}

If you're using .NET 4, there is a special folder enumeration ProgramFilesX86:

Environment.GetFolderPath(Environment.SpecialFolder.ProgramFilesX86)

Environment.GetEnvironmentVariable("PROGRAMFILES(X86)") ?? Environment.GetFolderPath(Environment.SpecialFolder.ProgramFiles)

Note, however, that the ProgramFiles(x86) environment variable is only available if your application is running 64-bit.

If your application is running 32-bit, you can just use the ProgramFiles environment variable whose value will actually be "Program Files (x86)".

One way would be to look for the "ProgramFiles(x86)" environment variable:

String x86folder = Environment.GetEnvironmentVariable("ProgramFiles(x86)");