要让IE使用多线程下载网页功能，必须要打开注册表子键（）

AHKEY_LOCAL_MACHINE/System/CurrentControlSet/Control/SessionManager/MemoryManagement

BHKEY_CURRENT_USER/Software/Microsoft/Windows/CurrentVersion/Explorer/Advanced

CHKEY_LOCAL_MACHINE/Software/Microsoft/InternetExplorer/Main

DHKEY_LOCAL_MACHINE/Software/Microsoft/Windows/CurrentVersion/InternetSettings