WIN7 Ubuntu双系统启动问题解决

问题陈述：

由于原来Ubuntu版本为10.04，太老，使用中有不少问题，决定重新装Ubuntu11.10. 把原来的Ubuntu安装盘格式化。

然后下载Ubuntu11.10， wubi.exe。两者放在一个文件夹。点击Wubi.exe，选择安装的位置：i:。

重启电脑：发现

Grub rescue, unknown file system.

error： unknown filesystem
进入：
grub rescue>
grub rescue> ls
(hd0) (hd0,8) (hd0,7) (hd0,6) (hd0,5) (hd0,3) (hd0,2) (hd0,1)

grub rescue> ls (hd0)
error：unknown filesystem

grub rescue> ls (hd0，8）
error：unknown filesystem
grub rescue> ls (hd0，7)
error：unknown filesystem
ls各个分区，都会出现以上错误。

解决问题：

网上搜集了很多关于GNUB的文章，发现没有一个可以解决问题。到了晚上，折腾的想放弃时，发现一个英文网站上有个不错的帖子：

http://superuser.com/questions/265957/grub-rescue-unknown-file-system-cant-boot-into-windows-7

里面详细的分析了解决方法。

现在系统启动时启动器已经由Windows启动管理器接管了，而不是由GRUB来启动。方法如下：

GRUB works in stages. First part of it is loaded from MBR (Master Boot Record), which points to secondary data located on your Linux partition that is required to proceed with next step of grub. From your description of the problem,
apparently you have deleted the second stage of your grub installation and grub isn't able to find it.

In order to get back your Windows 7 boot loader on your MBR, to allow you to boot into Windows 7, follow these steps:

1- Boot your computer from your Windows 7 install dvd.

2- Choose your language, time, and keyboard input on the first screen, and click next.

3- On next screen, you will be presented with three choices. Click on "Repair Your Computer", to enter recovery window. Now select "Command Prompt". At the command prompt, first change your directory to boot (cd boot), and then
type "bootsect /nt60 ALL /mdr". This will restore your windows boot loader onto your MBR.

一天的折腾，深刻体会到：

1)不到万不得已，不要重装系统。折腾折腾，可以学到不少东西。

2)Grub是个很好的引导多系统的Bootloader。

3)不要随意格式化硬盘。

4)使用Wubi安装Ubuntu非常方便。