Prova con spawnlp

void __fastcall TForm1::Button1Click(TObject *Sender)
{
spawnlp(P_WAIT,"c:\\windows\\system32\\notepad.exe ","c:\\windows\\system32\\notepad.exe",NULL);
}

oppure

void __fastcall TForm1::Button2Click(TObject *Sender)
{
spawnlp(P_OVERLAY,"c:\\windows\\system32\\notepad. exe","c:\\windows\\system32\\notepad.exe",NULL);
}