LoadModule function

Loads and executes an application or creates a new instance of an existing application.

Note  This function is provided only for compatibility with 16-bit versions of Windows. Applications should use the CreateProcess function.


DWORD LoadModule(
  LPCSTR lpModuleName,
  LPVOID lpParameterBlock



The file name of the application to be run. When specifying a path, be sure to use backslashes (), not forward slashes (/). If the lpModuleName parameter does not contain a directory path, the system searches for the executable file in this order:

  1. The directory from which the application loaded.
  2. The current directory.
  3. The system directory. Use the GetSystemDirectory function to get the path of this directory.
  4. The 16-bit system directory. There is no function that obtains the path of this directory, but it is searched. The name of this directory is System.
  5. The Windows directory. Use the GetWindowsDirectory function to get the path of this directory.
  6. The directories that are listed in the PATH environment variable.


A pointer to an application-defined LOADPARMS32 structure that defines the new application's parameter block.

Set all unused members to NULL, except for lpCmdLine, which must point to a null-terminated string if it is not used. For more information, see Remarks.

Return Value

If the function succeeds, the return value is greater than 31.

If the function fails, the return value is an error value, which may be one of the following values.

Return code/value Description
The system is out of memory or resources.
The .exe file is invalid.
The specified file was not found.
The specified path was not found.


The LOADPARMS32 structure has the following form:

typedef struct tagLOADPARMS32 { 
  LPSTR lpEnvAddress;  // address of environment strings 
  LPSTR lpCmdLine;     // address of command line 
  LPSTR lpCmdShow;     // how to show new program 
  DWORD dwReserved;    // must be zero 
Member Meaning
lpEnvAddress Pointer to an array of null-terminated strings that supply the environment strings for the new process. The array has a value of NULL as its last entry. A value of NULL for this parameter causes the new process to start with the same environment as the calling process.
lpCmdLine Pointer to a Pascal-style string that contains a correctly formed command line. The first byte of the string contains the number of bytes in the string. The remainder of the string contains the command line arguments, excluding the name of the child process. If there are no command line arguments, this parameter must point to a zero length string; it cannot be NULL.
lpCmdShow Pointer to a structure containing two WORD values. The first value must always be set to two. The second value specifies how the application window is to be shown and is used to supply the wShowWindow member of the STARTUPINFO structure to the CreateProcess function. See the description of the nCmdShow parameter of the ShowWindow function for a list of acceptable values.
dwReserved This parameter is reserved; it must be zero.

Applications should use the CreateProcess function instead of LoadModule. The LoadModule function calls CreateProcess by forming the parameters as follows.

CreateProcess parameter Argument used
lpszApplicationName lpModuleName
lpszCommandLine lpParameterBlock.lpCmdLine
lpProcessAttributes NULL
lpThreadAttributes NULL
bInheritHandles FALSE
dwCreationFlags 0
lpEnvironment lpParameterBlock.lpEnvAddress
lpCurrentDirectory NULL
lpStartupInfo The structure is initialized to zero. The cb member is set to the size of the structure. The wShowWindow member is set to the value of the second word of lpParameterBlock.lpCmdShow.
lpProcessInformation.hProcess The handle is immediately closed.
lpProcessInformation.hThread The handle is immediately closed.


Windows version Windows XP [desktop apps only] Windows Server 2003 [desktop apps only]
Target Platform Windows
Header winbase.h (include Windows.h)
Library Kernel32.lib
DLL Kernel32.dll

See Also


Dynamic-Link Library Functions