SHELLEXECUTEINFOA structure (shellapi.h)

Contains information used by ShellExecuteEx.


typedef struct _SHELLEXECUTEINFOA {
  DWORD     cbSize;
  ULONG     fMask;
  HWND      hwnd;
  LPCSTR    lpVerb;
  LPCSTR    lpFile;
  LPCSTR    lpParameters;
  LPCSTR    lpDirectory;
  int       nShow;
  void      *lpIDList;
  LPCSTR    lpClass;
  HKEY      hkeyClass;
  DWORD     dwHotKey;
  union {
    HANDLE hIcon;
    HANDLE hMonitor;
  HANDLE    hProcess;




Required. The size of this structure, in bytes.



A combination of one or more of the following values that indicate the content and validity of the other structure members:

SEE_MASK_DEFAULT (0x00000000) Use default values.
SEE_MASK_CLASSNAME (0x00000001) Use the class name given by the lpClass member. If both SEE_MASK_CLASSKEY and SEE_MASK_CLASSNAME are set, the class key is used.
SEE_MASK_CLASSKEY (0x00000003) Use the class key given by the hkeyClass member. If both SEE_MASK_CLASSKEY and SEE_MASK_CLASSNAME are set, the class key is used.
SEE_MASK_IDLIST (0x00000004) Use the item identifier list given by the lpIDList member. The lpIDList member must point to an ITEMIDLIST structure.
SEE_MASK_INVOKEIDLIST (0x0000000C) Use the IContextMenu interface of the selected item's shortcut menu handler. Use either lpFile to identify the item by its file system path or lpIDList to identify the item by its PIDL. This flag allows applications to use ShellExecuteEx to invoke verbs from shortcut menu extensions instead of the static verbs listed in the registry.
Note: SEE_MASK_INVOKEIDLIST overrides and implies SEE_MASK_IDLIST.
SEE_MASK_ICON (0x00000010) Use the icon given by the hIcon member. This flag cannot be combined with SEE_MASK_HMONITOR.
Note: This flag is used only in Windows XP and earlier. It is ignored as of Windows Vista.
SEE_MASK_HOTKEY (0x00000020) Use the keyboard shortcut given by the dwHotKey member.
SEE_MASK_NOCLOSEPROCESS (0x00000040) Use to indicate that the hProcess member receives the process handle. This handle is typically used to allow an application to find out when a process created with ShellExecuteEx terminates. In some cases, such as when execution is satisfied through a DDE conversation, no handle will be returned. The calling application is responsible for closing the handle when it is no longer needed.
SEE_MASK_CONNECTNETDRV (0x00000080) Validate the share and connect to a drive letter. This enables reconnection of disconnected network drives. The lpFile member is a UNC path of a file on a network.
SEE_MASK_NOASYNC (0x00000100) Wait for the execute operation to complete before returning. This flag should be used by callers that are using ShellExecute forms that might result in an async activation, for example DDE, and create a process that might be run on a background thread. (Note: ShellExecuteEx runs on a background thread by default if the caller's threading model is not Apartment.) Calls to ShellExecuteEx from processes already running on background threads should always pass this flag. Also, applications that exit immediately after calling ShellExecuteEx should specify this flag.

If the execute operation is performed on a background thread and the caller did not specify the SEE_MASK_ASYNCOK flag, then the calling thread waits until the new process has started before returning. This typically means that either CreateProcess has been called, the DDE communication has completed, or that the custom execution delegate has notified ShellExecuteEx that it is done. If the SEE_MASK_WAITFORINPUTIDLE flag is specified, then ShellExecuteEx calls WaitForInputIdle and waits for the new process to idle before returning, with a maximum timeout of 1 minute.

For further discussion on when this flag is necessary, see the Remarks section.

SEE_MASK_FLAG_DDEWAIT (0x00000100) The same as SEE_MASK_NOASYNC, use of that option is preferred.
SEE_MASK_DOENVSUBST (0x00000200) Expand any environment variables specified in the string given by the lpDirectory or lpFile member.
SEE_MASK_FLAG_NO_UI (0x00000400) Do not display user interface (UI) error dialogs that would normally be presented without this option. Security prompts are exempted and will still be shown.
SEE_MASK_UNICODE (0x00004000) Use this flag to indicate a Unicode application.
SEE_MASK_NO_CONSOLE (0x00008000) Use to inherit the parent's console for the new process instead of having it create a new console. It is the opposite of using a CREATE_NEW_CONSOLE flag with CreateProcess.
SEE_MASK_ASYNCOK (0x00100000) The execution can be performed on a background thread and the call should return immediately without waiting for the background thread to finish. Note that in certain cases ShellExecuteEx ignores this flag and waits for the process to finish before returning.
SEE_MASK_HMONITOR (0x00200000) Use this flag when specifying a monitor on multi-monitor systems. The monitor is specified in the hMonitor member. This flag cannot be combined with SEE_MASK_ICON.
SEE_MASK_NOZONECHECKS (0x00800000) Do not perform a zone check. This flag allows ShellExecuteEx to bypass zone checking put into place by IAttachmentExecute.
SEE_MASK_WAITFORINPUTIDLE (0x02000000) After the new process is created, wait for the process to become idle before returning, with a one minute timeout. See WaitForInputIdle for more details.
SEE_MASK_FLAG_LOG_USAGE (0x04000000) Indicates a user initiated launch that enables tracking of frequently used programs and other behaviors.
SEE_MASK_FLAG_HINST_IS_SITE (0x08000000) The hInstApp member is used to specify the IUnknown of an object that implements IServiceProvider. This object will be used as a site pointer. The site pointer is used to provide services to the ShellExecute function, the handler binding process, and invoked verb handlers.

ICreatingProcess can be provided to allow the caller to alter some parameters of the process being created.

This flag is supported in Windows 8 and later.

When this option is specified the call runs synchronously on the calling thread.


Type: HWND

Optional. A handle to the owner window, used to display and position any UI that the system might produce while executing this function.



A string, referred to as a verb, that specifies the action to be performed. The set of available verbs depends on the particular file or folder. Generally, the actions available from an object's shortcut menu are available verbs. This parameter can be NULL, in which case the default verb is used if available. If not, the "open" verb is used. If neither verb is available, the system uses the first verb listed in the registry. Unless there is a reason to limit the action to a specific verb, pass NULL to use the computed default. This is necessary in some cases, for example when specifying SEE_MASK_FLAG_NO_UI and the intention is to produce the "Open With" UI, if no apps are installed.

The following verbs are commonly used:

  • edit: Launches an editor and opens the document for editing. If lpFile is not a document file, the function will fail.
  • explore: Explores the folder specified by lpFile.
  • find: Initiates a search starting from the specified directory.
  • open: Opens the file specified by the lpFile parameter. The file can be an executable file, a document file, or a folder.
  • opeanas: Launches a picker UI allowing the user to select an app with which to open the file specified by the lpFile parameter.
  • print: Prints the document file specified by lpFile. If lpFile is not a document file, the function will fail.
  • properties: Displays the file or folder's properties.
  • runas: Launches an application as Administrator. User Account Control (UAC) will prompt the user for consent to run the application elevated or enter the credentials of an administrator account used to run the application.



The address of a null-terminated string that specifies the name of the file or object on which ShellExecuteEx will perform the action specified by the lpVerb parameter. The system registry verbs that are supported by the ShellExecuteEx function include "open" for executable files and document files and "print" for document files for which a print handler has been registered. Other applications might have added Shell verbs through the system registry, such as "play" for .avi and .wav files. To specify a Shell namespace object, pass the fully qualified parse name and set the SEE_MASK_INVOKEIDLIST flag in the fMask parameter.

Note: If the SEE_MASK_INVOKEIDLIST flag is set, you can use either lpFile or lpIDList to identify the item by its file system path or its PIDL respectively. One of the two values—lpFile or lpIDList—must be set.
Note: If the path is not included with the name, the current directory is assumed.



Optional. The address of a null-terminated string that contains the application parameters. The parameters must be separated by spaces. If the lpFile member specifies a document file, lpParameters should be NULL.



Optional. The address of a null-terminated string that specifies the name of the working directory. If this member is NULL, the current directory is used as the working directory.


Type: int

Required. Flags that specify how an application is to be shown when it is opened; one of the SW_ values listed for the ShellExecute function. If lpFile specifies a document file, the flag is simply passed to the associated application. It is up to the application to decide how to handle it.



[out] If SEE_MASK_NOCLOSEPROCESS is set and the ShellExecuteEx call succeeds, it sets this member to a value greater than 32. If the function fails, it is set to an SE_ERR_XXX error value that indicates the cause of the failure. Although hInstApp is declared as an HINSTANCE for compatibility with 16-bit Windows applications, it is not a true HINSTANCE. It can be cast only to an int and compared to either 32 or the following SE_ERR_XXX error codes.

Error Code Reason
SE_ERR_FNF (2) File not found.
SE_ERR_PNF (3) Path not found.
SE_ERR_ACCESSDENIED (5) Access denied.
SE_ERR_OOM (8) Out of memory.
SE_ERR_DLLNOTFOUND (32) Dynamic-link library not found.
SE_ERR_SHARE (26) Cannot share an open file.
SE_ERR_ASSOCINCOMPLETE (27) File association information not complete.
SE_ERR_DDETIMEOUT (28) DDE operation timed out.
SE_ERR_DDEFAIL (29) DDE operation failed.
SE_ERR_DDEBUSY (30) DDE operation is busy.
SE_ERR_NOASSOC (31) File association not available.



The address of an absolute ITEMIDLIST structure (PCIDLIST_ABSOLUTE) to contain an item identifier list that uniquely identifies the file to execute. This member is ignored if the fMask member does not include SEE_MASK_IDLIST or SEE_MASK_INVOKEIDLIST.



The address of a null-terminated string that specifies one of the following:

  • A ProgId. For example, "Paint.Picture".
  • A URI protocol scheme. For example, "http".
  • A file extension. For example, ".txt".
  • A registry path under HKEY_CLASSES_ROOT that names a subkey that contains one or more Shell verbs. This key will have a subkey that conforms to the Shell verb registry schema, such as shell\verb name.

This member is ignored if fMask does not include SEE_MASK_CLASSNAME.


Type: HKEY

A handle to the registry key for the file type. The access rights for this registry key should be set to KEY_READ. This member is ignored if fMask does not include SEE_MASK_CLASSKEY.



A keyboard shortcut to associate with the application. The low-order word is the virtual key code, and the high-order word is a modifier flag (HOTKEYF_). For a list of modifier flags, see the description of the WM_SETHOTKEY message. This member is ignored if fMask does not include SEE_MASK_HOTKEY.




A handle to the icon for the file type. This member is ignored if fMask does not include SEE_MASK_ICON. This value is used only in Windows XP and earlier. It is ignored as of Windows Vista.



A handle to the monitor upon which the document is to be displayed. This member is ignored if fMask does not include SEE_MASK_HMONITOR.



A handle to the newly started application. This member is set on return and is always NULL unless fMask is set to SEE_MASK_NOCLOSEPROCESS. Even if fMask is set to SEE_MASK_NOCLOSEPROCESS, hProcess will be NULL if no process was launched. For example, if a document to be launched is a URL and an instance of Internet Explorer is already running, it will display the document. No new process is launched, and hProcess will be NULL.

Note: ShellExecuteEx does not always return an hProcess, even if a process is launched as the result of the call. For example, an hProcess does not return when you use SEE_MASK_INVOKEIDLIST to invoke IContextMenu.


The SEE_MASK_NOASYNC flag must be specified if the thread calling ShellExecuteEx does not have a message loop or if the thread or process will terminate soon after ShellExecuteEx returns. Under such conditions, the calling thread will not be available to complete the DDE conversation, so it is important that ShellExecuteEx complete the conversation before returning control to the calling application. Failure to complete the conversation can result in an unsuccessful launch of the document.

If the calling thread has a message loop and will exist for some time after the call to ShellExecuteEx returns, the SEE_MASK_NOASYNC flag is optional. If the flag is omitted, the calling thread's message pump will be used to complete the DDE conversation. The calling application regains control sooner, since the DDE conversation can be completed in the background.

To include double quotation marks in lpParameters, enclose each mark in a pair of quotation marks, as in the following example.

sei.lpParameters = "An example: \"\"\"quoted text\"\"\"";

In this case, the application receives three parameters: An, example:, and "quoted text".


The shellapi.h header defines SHELLEXECUTEINFO as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.


Requirement Value
Minimum supported client Windows XP [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Header shellapi.h