最近，相信很多使用wubi在Windows下安裝Ubuntu的系統更新後無法再進入系統的問題，讓人不寒而慄，有很多人為此不得不重裝系統。
出現此問題的原因在於更新Ubuntu時選擇更新grub組件，以至於把引導區grub破壞，這也是個不小的bug吧？？？
下面說說如何通過U盤啟動盤來修復Ubuntu。當然，你得有個1G以上的U盤，再有，你的主板必須支持U盤啟動！
首先，當然是准備一個1G以上容量的U盤，用來制作可啟動U盤；
其次，到官網上下載Ubuntu desktop鏡像文件。Ubuntu Desktop鏡像一般700多兆，從而可以把它寫到1G大的U盤上，可以從Ubuntu官網下載10.4的鏡像文件。
用UltraISO將其寫入U盤，制作成可啟動的U盤。自作完成後重啟電腦，選擇從U盤啟動。
由於你寫入U盤的實際上是個像光盤一樣的Ubuntu安裝盤，所以進入U盤Ubuntu後，你可以選擇不安裝而直接試用體驗Ubuntu，這也是本方法的關鍵所在，利用LiveCD，我們可以暫時進入系統，借以修復原有系統！
進入Ubuntu系統後，啟動命令終端，輸入如下指令，在線安裝lilo和mbr：
ubuntu@ubuntu:~$ sudo apt-get install lilo
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed:
mbr
Suggested packages:
lilo-doc
The following NEW packages will be installed:
lilo mbr
0 upgraded, 2 newly installed, 0 to remove and 408 not upgraded.
Need to get 413kB of archives.
After this operation, 1,315kB of additional disk space will be used.
Do you want to continue [Y/n]? y
Get:1 http://mirror.bjtu.edu.cn/ubuntu/ lucid/main mbr 1.1.10-2 [23.0kB]
Get:2 http://mirror.bjtu.edu.cn/ubuntu/ lucid/main lilo 1:22.8-8ubuntu1 [390kB]
Fetched 413kB in 3s (124kB/s)
Preconfiguring packages ...
Selecting previously deselected package mbr.
(Reading database ... 129801 files and directories currently installed.)
Unpacking mbr (from .../archives/mbr_1.1.10-2_i386.deb) ...
Selecting previously deselected package lilo.
Unpacking lilo (from .../lilo_1%3a22.8-8ubuntu1_i386.deb) ...
Processing triggers for man-db ...
Setting up mbr (1.1.10-2) ...
Setting up lilo (1:22.8-8ubuntu1) ...
WARNING: kernel & initrd not found in the root directory (/vmlinuz & /initrd.img)
WARNING: Do NOT reboot or LILO may fail to boot if your kernel+initrd is large.
WARNING: Please read /usr/share/doc/lilo/README.Debian
ubuntu@ubuntu:~$
安裝過程中，會得到如下lilo的配置提示，按OK就行了：
Package configuration
┌───────────────────────────┤ Configuring lilo ├────────────────────────────┐
│ │
│ LILO configuration │
│ │
│ It seems to be your first LILO installation. It is absolutely necessary │
│ to run liloconfig(8) when you complete this process and execute │
│ /sbin/lilo after this. │
│ │
│ LILO won't work if you don't do this. │
│ │
│ <Ok> │
│ │
└───────────────────────────────────────────────────────────────────────────┘
然後使用lilo修復系統：
ubuntu@ubuntu:~$ sudo lilo -M /dev/sda mbr
Backup copy of /dev/sda in /boot/boot.0800
The Master Boot Record of /dev/sda has been updated.
ubuntu@ubuntu:~$
修復完成，重啟系統：
ubuntu@ubuntu:~$ sudo -s -H
root@ubuntu:/home/ubuntu# reboot
OK了，相信重啟後選擇進入系統的畫面就出現了，是不是很簡單？
