系统win8.1，virualbox装ubuntu 14.04启动不了

不能为虚拟电脑 Ubuntu 打开一个新任务.
The virtual machine *Ubuntu* has terminated unexpectedly during startup with exit code 1.
返回 代码: E_FAIL (0x80004005)
组件: Machine
界面: IMachine {480cf695-2d8d-4256-9c7c-cce4184fa048}