每次安装完Windows 都会把Grub给冲掉，这也是微软霸道的一面吧。
Ubuntu升级很快，所以也懒得刻CD了，就是搞个U盘，每次要用的时候就花个20分钟重搞一下，不管是做安装还是其他用途都很方便。

[url]http://www.pendrivelinux.com/[/url]
上有很多做启动U盘的选择，随便贴一个在Windows下的

1. 用Fat16或者Fat32的格式格式化U盘
2. 下载 运行 Ub8convert2.exe , 它将在硬盘上创建一个 Ubuntu8 目录
3. 下载 Ubuntu 8.04.1 ISO 光盘映像， 并保存在 Ubuntu8 目录下
4. 在 Ubuntu8 文件夹里面, 点击 fixu8.bat 然后根据提示一步一步完成
5. 上述脚本运行完毕后即可重启然后在Bios里面设置U盘启动。

注意事项：
我使用的时候fixu8.bat有个Bug, 就是读不到盘符，不过修改Bat文件即可，修改时要小心，不要把不该格的盘格了 修改后的bat文件见附录（H是U盘）。

修复Grub:


用U盘启动后运行：

%> sudo grub
gurb> find /boot/grub/stage1
(hd0,4)
gurb> root (hd0,4)
grub> setup (hd0)
grub> quit

附录
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
rem This batch script was created by ?2007 Lance [url]http://pendrivelinux.com[/url]
rem The included syslinux.cfg file was modified by Lance @ [url]http://pendrivelinux.com[/url] as well
rem 7-Zip Copyright (C) 1999-2007 Igor Pavlovis [url]http://7-zip.org[/url] is being redistributed with written permission
rem Ubuntu is a registered trademark of Canonical Ltd. ?2007 Canonical Ltd. [url]http://ubuntu.com[/url]
@echo off
cls
echo.
echo ===========================================================================
echo \\\ Pendrivelinux.com USB Linux file preparation script for Ubuntu 8.04 ///
echo ===========================================================================
echo.
echo.
echo?? This script will extract your Ubuntu 8.04 ISO to you USB flash drive
echo?? using 7-Zip. It will then prepare the filesystem for USB usage.
echo?? Once finished, you should have a ready to run Ubuntu 8 flash drive
echo.
echo.
echo?? Please note that this batch file and any included software is being
echo?? provided as is without warranty,in hopes that it will be useful.
echo?? USE AT YOUR OWN RISK!!
echo.
echo.


set /p drive=H


:proceed
cls
echo.
echo Would you like to format flash drive %drive%:?
echo.
echo Type y or n and press Enter
set /p ok=
if ?ok%?== ‘y?goto yes
if ?ok%?== ‘Y?goto yes
if ?ok%?== ‘n?goto no
if ?ok%?== ‘N?goto no
cls

:yes
cls
echo Pre-Stage Format:
echo First, let's ensure that the flash drive is inserted
echo.
format H: /FS:fat32 /V:Ubuntu8 /Q
cls

:no
cls
echo Stage 1:
7-Zip\7z x *.iso -x!bin -x!programs -x!isolinux\isolinux.txt -x![BOOT] -oH:
cls
echo Stage 2:
echo Please wait while we prepare the files and copy them to your flash drive...
echo.
mkdir H:\syslinux\win32
copy syslinux\win32\*.* H:\syslinux\win32
copy backg.png H:
copy syslinux.cfg H:
copy vesamenu.c32 H:
copy makeboot.bat H:
H:
copy isolinux\*.*
rd isolinux /s/q
del isolinux.bin
call h:\makeboot.bat