LFS进行一半后重启，不成功

按照LFS 6.2中文手册做到6.8步，之后由于要断电下班，所以shutdown -h now了，但今天上班时虚拟机却启动不了了，提示信息是：
The master boot record (MBR) of this virtual machine's hard disk does not contain valid bootstrap code. It is likely that the MBR was corrupted by an incorrect guest operating system installation or some other reason. The virtual machine cannot continue and will now power off. (For advanced users: the MBR is the last disk sector accessed by the virtual machine before the error.) Please consult our Web site at "http://www.vmware.com/info?id=18" for common troubleshooting help.

*** Virtual machine kernel stack fault (hardware reset) ***
The virtual machine just suffered a stack fault in kernel mode. On a real computer, this would amount to a reset of the processor. It can be caused by an incorrect configuration of the virtual machine, a bug in the operating system, or a problem in the VMware Workstation software. Press OK to reboot virtual machine or Cancel to shut it down.

请问怎么才能进入我上次操作后的状态？ 我的livecd是6.2.5版本的。

设置虚拟机从光驱启动

做过了，还是没用，根本进入不了BIOS啊！ 按Delete、F2都没用，同样的错误对话框。

问题已经解决，汗自己一下，之所以进不了BIOS，是因为启动虚拟机时没有把鼠标焦点放在系统里面，这样任何键盘操作都没用