Here are the error codes I found for the ShellExecute command listed by Microsoft.

#define ERROR_BAD_FORMAT 11L
#define ERROR_PATH_NOT_FOUND 3L
#define ERROR_FILE_NOT_FOUND 2L

#define SE_ERR_FNF 2 // file not found
#define SE_ERR_PNF 3 // path not found
#define SE_ERR_ACCESSDENIED 5 // access denied
#define SE_ERR_OOM 8 // out of memory
#define SE_ERR_DLLNOTFOUND 32

#endif /* WINVER >= 0x0400 */ In other words; when using 95 or NT

/* error values for ShellExecute() beyond the regular WinExec() codes */
#define SE_ERR_SHARE 26
#define SE_ERR_ASSOCINCOMPLETE 27
#define SE_ERR_DDETIMEOUT 28
#define SE_ERR_DDEFAIL 29
#define SE_ERR_DDEBUSY 30
#define SE_ERR_NOASSOC 31


Rob