This function executes the registry command found from the default value of an arbitrary registry key.


RunRegCommand (
    HWND hWnd,
    HKEY hKey,
    LPCWSTR pszSubKey);


The hWnd argument provides the window handle to use for message boxes while trying to execute the command.

The hKey argument provides a handle to an open registry key.

The pszSubKey argument provides the address of a null-terminated string that names a subkey in which to find the registry command.

Return Value

The function returns zero for success, else an error code.


At its simplest, the registry command is just the string data for the default value from the registry key key\subkey, where

Command Reference

However, it is allowed that this string data is not the command itself but is instead a reference to some other registry value that supplies the command. This case applies if the string data has the form root:path\value, where

The registry command is then the string data for value in the key represented by path in the branch denoted by root. If value is empty, meaning that the reference has a trailing backslash, then the command is the string data for the default value in this key. The three valid prefixes that identify the root represent HKEY_CLASSES_ROOT, HKEY_CURRENT_USER and HKEY_LOCAL_MACHINE respectively.


If a command is not found, whether directly or by reference, the function fails, with E_FAIL as the error code.

The function intreprets the registry command as a pathname, possibly in quotes, to an executable file, followed by command-line arguments. Execution is through ShellExecuteEx, in a normal window. If running on an NT version greater than 5.00 or on NT version 5.00 in a build later than 2195, execution of the command contributes to the executable’s usage count.


The RunRegCommand function is exported from SHLWAPI as ordinal 469 in late builds of version 5.00 and then in all higher versions.

Though this function dates from as long ago as 2000, it was still not documented by Microsoft in the MSDN Library at least as late as the CD edition dated January 2004.