更新了ubuntu，启动虚拟电脑时会报错：

 NS_ERROR_FAILURE (0x80004005) Machine IMachine {5eaa9319-62fc-4b0a-843c-0cb1940f8a91} 

并且有如下提示：

Kernel driver not installed (rc=-1908)

The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a permission problem with /dev/vboxdrv. Please reinstall the kernel module by executing

'/etc/init.d/vboxdrv setup'

as root. If it is available in your distribution, you should install the DKMS package first. This package keeps track of Linux kernel changes and recompiles the vboxdrv kernel module if necessary.

大概是说内核驱动没有安装，估计是ubuntu内核更新后virtualbox没有相应更新，察看了下ubuntu的内核，果然更新了：

内核 Linux 3.2.0-25-generic

从3.2.0-24更新到了3.2.0-25.

按照提示信息，执行

sudo /etc/init.d/vboxdrv setup

运行情况：

* Stopping VirtualBox kernel modules                                    [ OK ] 
 * Uninstalling old VirtualBox DKMS kernel modules                       [ OK ] 
 * Trying to register the VirtualBox kernel modules using DKMS                  
 * Failed, trying without DKMS
 * Recompiling VirtualBox kernel modules                                 [ OK ] 
 * Starting VirtualBox kernel modules                                    [ OK ] 

然后就可以启动虚拟电脑了。