如果你安裝了Win7和Win8，啟動的時候得先啟動到Win8然后再啟動到Win7，很懷念原來的啟動選擇器，這里給你方法了~
當前系統是Win8的輸入
bcdedit /set {current} bootmenupolicy Legacy
當前系統是Win7的輸入
bcdedit /set {default} custom:250000c2 0
恢復Modern UI風格啟動菜單
bcdedit /set {current} bootmenupolicy standard