ubuntu双系统开机默认启动windows设置

一、

我的电脑原来先装的Windows XP，后来由于工作需要，又装了一个Linux_Ubuntu 9.04,我设置了定时开机，但是总是默认启动到Ubuntu环境。

通过下面的操作把Windows XP改为默认启动系统：

启动ubuntu后，输入：sudo gedit /boot/grub/menu.lst

输入正确密码，打开menu.lst。

从第一行往下看，找到第一个开头没有#的行

default 0

继续往下看，找到所有以title开头的行（注意，以＃开头的都不要理）。

我的文件中，以title开头的共(开头没有#)有7行，依次为：

title Ubuntu 8.04.1, kernel 2.6.24-21-generic

title Ubuntu 8.04.1, kernel 2.6.24-21-generic (recovery mode)

title Ubuntu 8.04.1, kernel 2.6.24-16-generic

title Ubuntu 8.04.1, kernel 2.6.24-16-generic (recovery mode)

title Ubuntu 8.04.1, memtest86+

title Other operating systems:

title Windows NT/2000/XP

 

这些行不是像这样连在一起的，它们分散在文件中。把这7行写一起，为的是让我们看得清楚些。事实上，除去每行前面的title，这7行就是我开机时出现的启动菜单项，系统在启动时读的就是该文件。

default 0

表示默认情况下启动以上菜单上第1行(0+1)的系统。

我们看到windows处于第7(6+1)行，所以现在把default的值改为6，保存文件，重启系统，默认启动的系统就改为Windows了。

 

二、在Ubuntu 10.04中，并没有menu.lst文件，文件名已经变成grub.cfg。

更改操作如下：

1、备份原文件为grub.cfg.bak

代码:sudo cp /boot/grub/grub.cfg /boot/grub/grub.cfg.bak

2、修改启动顺序

代码:sudo gedit /boot/grub/grub.cfg

在打开顶文件中找到set default="0"，可以看出默认是第一项(从0开始计数)。

然后找到以menuentry开头的所有行，下面是我电脑上该文件的内容，一共7行，最后一行是Windows XP项。以我的文件内容为例，我只要set default="6(注意：从0开始计数)就可以把Windows XP改为默认启动系统。

menuentry 'Ubuntu，Linux 2.6.32-22-generic'

menuentry 'Ubuntu，Linux 2.6.32-22-generic (恢复模式)'

menuentry 'Ubuntu，Linux 2.6.32-21-generic'

menuentry 'Ubuntu，Linux 2.6.32-21-generic (恢复模式)'

menuentry "Memory test (memtest86+)"

menuentry "Memory test (memtest86+, serial console 115200)"

menuentry "Microsoft Windows XP Professional (on /dev/sda1)"

 

 

三、当系统“/boot/grub/   ”里根本没有“menu.lst”这个文件时，具体步骤如下：

 

1.用root身份登录Ubuntu

默认下是静止本地root登录的，解决方法是：系统－系统管理－登录窗口－安全－选择允许本地系统管理员登录；sudo passwd回车；输入你的密码；为root设定密码；重复；就可以登录root了。

 

2./boot/grub/目录下没有menu.lst这个文件，可以自己新建一个，然后把下面这些代码复制到新建的menu.lst这个文件里，将default的值改成4，保存即可。

 

开始：

# menu.lst - See: grub(8), info grub, update-grub(8)

#            grub-install(8), grub-floppy(8),

#            grub-md5-crypt, /usr/share/doc/grub

#            and /usr/share/doc/grub-doc/.

 

## default num

# Set the default entry to the entry number NUM. Numbering starts from 0, and

# the entry number 0 is the default if the command is not used.

#

# You can specify 'saved' instead of a number. In this case, the default entry

# is the entry saved with the command 'savedefault'.

# WARNING: If you are using dmraid do not use 'savedefault' or your

# array will desync and will not let you boot your system.

default        0

 

## timeout sec

# Set a timeout, in SEC seconds, before automatically booting the default entry

# (normally the first entry defined).

timeout        10

 

## hiddenmenu

# Hides the menu by default (press ESC to see the menu)

#hiddenmenu

 

# Pretty colours

#color cyan/blue white/blue

 

## password ['--md5'] passwd

# If used in the first section of a menu file, disable all interactive editing

# control (menu entry editor and command-line) and entries protected by the

# command 'lock'

# e.g. password topsecret

#      password --md5 $1$gLhU0/$aW78kHK1QfV3P2b2znUoe/

# password topsecret

 

#

# examples

#

# title        Windows 95/98/NT/2000

# root        (hd0,0)

# makeactive

# chainloader    +1

#

# title        Linux

# root        (hd0,1)

# kernel    /vmlinuz root=/dev/hda2 ro

#

 

#

# Put static boot stanzas before and/or after AUTOMAGIC KERNEL LIST

 

### BEGIN AUTOMAGIC KERNELS LIST

## lines between the AUTOMAGIC KERNELS LIST markers will be modified

## by the debian update-grub script except for the default options below

 

## DO NOT UNCOMMENT THEM, Just edit them to your needs

 

## ## Start Default Options ##

## default kernel options

## default kernel options for automagic boot options

## If you want special options for specific kernels use kopt_x_y_z

## where x.y.z is kernel version. Minor versions can be omitted.

## e.g. kopt=root=/dev/hda1 ro

##      kopt_2_6_8=root=/dev/hdc1 ro

##      kopt_2_6_8_2_686=root=/dev/hdc2 ro

# kopt=root=UUID=04d0edaf-6a91-46c5-8bec-35a97eeaa27f ro

 

## default grub root device

## e.g. groot=(hd0,0)

# groot=04d0edaf-6a91-46c5-8bec-35a97eeaa27f

 

## should update-grub create alternative automagic boot options

## e.g. alternative=true

##      alternative=false

# alternative=true

 

## should update-grub lock alternative automagic boot options

## e.g. lockalternative=true

##      lockalternative=false

# lockalternative=false

 

## additional options to use with the default boot option, but not with the

## alternatives

## e.g. defoptions=vga=791 resume=/dev/hda5

# defoptions=quiet splash

 

## should update-grub lock old automagic boot options

## e.g. lockold=false

##      lockold=true

# lockold=false

 

## Xen hypervisor options to use with the default Xen boot option

# xenhopt=

 

## Xen Linux kernel options to use with the default Xen boot option

# xenkopt=console=tty0

 

## altoption boot targets option

## multiple altoptions lines are allowed

## e.g. altoptions=(extra menu suffix) extra boot options

##      altoptions=(recovery) single

# altoptions=(recovery mode) single

 

## controls how many kernels should be put into the menu.lst

## only counts the first occurence of a kernel, not the

## alternative kernel options

## e.g. howmany=all

##      howmany=7

# howmany=all

 

## specify if running in Xen domU or have grub detect automatically

## update-grub will ignore non-xen kernels when running in domU and vice versa

## e.g. indomU=detect

##      indomU=true

##      indomU=false

# indomU=detect

 

## should update-grub create memtest86 boot option

## e.g. memtest86=true

##      memtest86=false

# memtest86=true

 

## should update-grub adjust the value of the default booted system

## can be true or false

# updatedefaultentry=false

 

## should update-grub add savedefault to the default options

## can be true or false

# savedefault=false

 

## ## End Default Options ##

 

title        Ubuntu 9.04, kernel 2.6.28-11-generic

uuid        04d0edaf-6a91-46c5-8bec-35a97eeaa27f

kernel        /boot/vmlinuz-2.6.28-11-generic root=UUID=04d0edaf-6a91-46c5-8bec-35a97eeaa27f ro quiet splash

initrd        /boot/initrd.img-2.6.28-11-generic

quiet

 

title        Ubuntu 9.04, kernel 2.6.28-11-generic (recovery mode)

uuid        04d0edaf-6a91-46c5-8bec-35a97eeaa27f

kernel        /boot/vmlinuz-2.6.28-11-generic root=UUID=04d0edaf-6a91-46c5-8bec-35a97eeaa27f ro single

initrd        /boot/initrd.img-2.6.28-11-generic

 

title        Ubuntu 9.04, memtest86+

uuid        04d0edaf-6a91-46c5-8bec-35a97eeaa27f

kernel        /boot/memtest86+.bin

quiet

 

### END DEBIAN AUTOMAGIC KERNELS LIST

 

# This is a divider, added to separate the menu items below from the Debian

# ones.

title        Other operating systems:

root

 

 

# This entry automatically added by the Debian installer for a non-linux OS

# on /dev/sda1

title        Microsoft Windows XP Professional

rootnoverify    (hd0,0)

savedefault

makeactive

chainloader    +1

 

结束。

问题得到解决了吧！呵呵！