IsWow64Process (Win32 API) | Microsoft Learn

IsWow64Process

The IsWow64Process function determines whether the current process is running under WOW64 (Windows 32-bit On Windows 64-bit). WOW64 is a layer of the operating system that allows 32-bit applications to run on 64-bit versions of Windows.

Syntax

BOOL IsWow64Process(
  HANDLE  hProcess,
  PBOOL   Wow64Process
);

Parameters

Parameter	Type	Description
`hProcess`	`HANDLE`	A handle to the process to be queried. This handle must have the `PROCESS_QUERY_INFORMATION` access right. For more information, see Process Security and Access Rights.
`Wow64Process`	`PBOOL`	A pointer to a boolean value that receives the WOW64 status. If this parameter is `TRUE`, the process is running under WOW64. If this parameter is `FALSE`, the process is a native 64-bit process.

Return value

If the function succeeds, the return value is a nonzero value.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

The IsWow64Process function returns whether the process identified by hProcess is a 32-bit process running under WOW64. This is important for detecting whether your application is running in a 32-bit or 64-bit environment.

To check the current process, you can pass GetCurrentProcess() as the hProcess parameter.

Important: This function is not supported on 32-bit versions of Windows. If you call this function on a 32-bit operating system, the function will fail and GetLastError will return ERROR_NOT_SUPPORTED.

Requirements