在程序中，运行其他程序 - C++ Builder / Windows SDK/API
以下是书上的代码，功能是实现在程序中运行其他程序，用ShellExecute()函数就没问题，但是用CreateProcess()函数，失败的几率就很高，为什么呢？哪里错了，请问该怎么改？

C/C++ code

//---------------------------------------void __fastcall TForm1::Button2Click(TObject *Sender){    AnsiString Path;    Path.SetLength(256);    Path.SetLength(GetSystemDirectory(Path.c_str(),Path.Length()));    ShellExecute(this->Handle,"open","Calc.exe",NULL,Path.c_str(),SW_SHOWNORMAL);}//---------------------------------------void __fastcall TForm1::Button1Click(TObject *Sender){    AnsiString FileName;    FileName.SetLength(256);    FileName.SetLength(GetSystemDirectory(FileName.c_str(),                            FileName.Length()));    FileName = FileName + "\\Calc.exe";    LPSTARTUPINFO StartupInfo = new STARTUPINFO;    SECURITY_ATTRIBUTES *psap = new SECURITY_ATTRIBUTES;    psap->lpSecurityDescriptor = NULL;    psap->bInheritHandle = true;    psap->nLength = sizeof(psap);    SECURITY_ATTRIBUTES *psat = new SECURITY_ATTRIBUTES;    psat->lpSecurityDescriptor = NULL;    psat->bInheritHandle = true;    psat->nLength = sizeof(psat);    LPPROCESS_INFORMATION newProcess = new PROCESS_INFORMATION;    int res = CreateProcess(FileName.c_str(),NULL,psap,psat,true,        CREATE_SEPARATE_WOW_VDM | DETACHED_PROCESS | NORMAL_PRIORITY_CLASS,        NULL,NULL,StartupInfo,newProcess);    int i = GetLastError();    ShowMessage(IntToStr(res)+"  "+IntToStr(i));}//---------------------------------------

C/C++ code

char szPath[MAX_PATH] = { 0 }; 
 ::GetSystemDirectory(szPath, MAX_PATH); 
  
 AnsiString FileName = AnsiString().sprintf("%s\\Calc.exe", szPath); 
  
 STARTUPINFO si; 
 ZeroMemory(&si, sizeof(si)); 
 si.cb = sizeof(STARTUPINFO); 
  
 PROCESS_INFORMATION pi; 
 ZeroMemory(&pi, sizeof(pi)); 
  
 SECURITY_ATTRIBUTES psap; 
 psap.lpSecurityDescriptor = NULL; 
 psap.bInheritHandle = true; 
 psap.nLength = sizeof(psap); 
  
 SECURITY_ATTRIBUTES psat; 
 psat.lpSecurityDescriptor = NULL; 
 psat.bInheritHandle = true; 
 psat.nLength = sizeof(psat); 
  
 BOOL bRet = ::CreateProcess( 
     FileName.c_str(), 
     NULL, 
     &psap, 
     &psat, 
     true, 
     CREATE_SEPARATE_WOW_VDM | DETACHED_PROCESS | NORMAL_PRIORITY_CLASS, 
     NULL, 
     NULL, 
     &si, 
     &pi); 
  
 DWORD dwLastError = ::GetLastError(); 
  
 ShowMessage(AnsiString().sprintf("CreateProcess执行%s GetLastError: %d", 
     bRet? "成功.": "失败!", dwLastError));