首先，当然是准备一个1G以上容量的U盘，用来制作可启动U盘;

其次，到官网上下载Ubuntu desktop镜像文件。Ubuntu Desktop镜像一般700多兆，从而可以把它写到1G大的U盘上，可以从Ubuntu官网下载镜像文件。

用UltraISO将其写入U盘，制作成可启动的U盘。自作完成后重启电脑，选择从U盘启动。

由于你写入U盘的实际上是个像光盘一样的Ubuntu安装盘，所以进入U盘Ubuntu后，你可以选择不安装而直接试用体验Ubuntu，这也是本方法的关键所在，利用LiveCD，我们可以暂时进入系统，借以修复原有系统!下面就跟着来看具体的步骤吧：

进入Ubuntu系统后，启动命令终端，输入如下指令，在线安装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 lucid/main mbr 1.1.10-2 [23.0kB]

Get:2 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:~$

安装过程中，会得到如下lilo的配置提示，按OK就行了：

Package configuration