How to retrieve correct path of either system32 or SysWOW64?

Question

I have a 32-bit process that can run either in 32-bit or 64-bit Windows. So, naturally, if the process tried to access the file c:\windows\system32\file.ext, it would be redirected to c:\windows\SysWOW64\file.ext. So far so good - I don't want to disable the redirection.

My problem is that my process doesn't actually access the file - instead it just takes its path and writes it into a text file, and I want that text file to read SysWOW64 on a 64-bit system, and system32 on a 32-bit system. How can I do that?

Answer 1

The following code will return the correct system directory (system32\syswow64):

[DllImport("shell32.dll")]
public static extern bool SHGetSpecialFolderPath(
    IntPtr hwndOwner, [Out]StringBuilder lpszPath, int nFolder, bool fCreate
);

public static string GetSystemDirectory()
{
    StringBuilder path = new StringBuilder(260);
    NativeMethods.SHGetSpecialFolderPath(IntPtr.Zero, path, 0x0029, false);
    return path.ToString();
}

On x86 you'll get %windir%\System32 On X64 you'll get %windir%\SysWow64

Hope this is helpful

Answer 2

if I understood it correctly, you can use SHGetSpecialFolderPath passing CSIDL_SYSTEMX86 to the csidl parameter. The documentation for the valid csidl's states that a 32 bit process will get:

• %windir%\system32 on a 32 bits OS
• %windir%\syswow64 on a 64 bits OS

Best regards