从网上找到一个函数。
void CShellClass::Format(char m_TransData)//m_TransData为磁盘符。
{
  CDiskInfo win;
  win.GetPlatform();
  char cTemp[256];
  GetSystemDirectory(cTemp,100);
  if(win.dwCurrentPlatform==Win2000)
  {
    //WINNT以上操作系统
    char *FormatW2K = "CMD.EXE";
    char FormatW2KParam[100] = {0};
    sprintf(FormatW2KParam,
"format.com %c:/force/q/u/x/V:MISC\"",m_TransData);
TRACE("%s\n",FormatW2KParam);
    ShellExecute(NULL,"open",FormatW2K,FormatW2KParam,NULL,SW_HIDE);
  }
  else
  {
    //WIN98操作系统
   char *FormatW9X = "COMMAND.COM";
   char FormatW2KParam[100] = {0};
   sprintf(FormatW2KParam,
   "/C\"format.com %c:/autotest/q/u/V:MISC\""//“/C”是什么意思?
   ,m_TransData);
   ShellExecute(NULL,"open",FormatW9X,FormatW2KParam,NULL,SW_HIDE);
  }