HKEY hkey; //注册表句柄，标示是否打开注册表成功
DWORD dwSize = MAX_PATH;
TCHAR string[MAX_PATH];
LONG lRet = RegOpenKeyEx(HKEY_LOCAL_MACHINE,pathDir,0,KEY_READ,&hkey); //打开注册表路径（不含键值）,pathDir:注册表路径
if(lRet != ERROR_SUCCESS)
{
return S_OK;
}
lRet = RegQueryValueEx(hkey, keyValue, NULL, REG_NONE,(LPBYTE)string,&dwSize); //将键值读取到string中，keyValue，注册表键名称
