[Résolu] Problème grub

Bonsoir,
J'ai vista et ubuntu en dual boot avec grub.
Le problème c'est que depuis peu (et je ne sais pourquoi) grub démarre mais lance directement ubuntu. J'ai plus le choix de l'os.
Que dois-je faire?

le voilà:

# 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 0

## 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=f2499860-0ecc-4195-8482-e954129ddf70 ro

## default grub root device
## e.g. groot=(hd0,0)
# groot=f2499860-0ecc-4195-8482-e954129ddf70

## 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 2.6.28-13-generic
uuid f2499860-0ecc-4195-8482-e954129ddf70
kernel /boot/vmlinuz-2.6.28-13-generic root=UUID=f2499860-0ecc-4195-8482-e954129ddf70 ro quiet splash
initrd /boot/initrd.img-2.6.28-13-generic
quiet

title Ubuntu 9.04, kernel 2.6.28-13-generic (recovery mode)
uuid f2499860-0ecc-4195-8482-e954129ddf70
kernel /boot/vmlinuz-2.6.28-13-generic root=UUID=f2499860-0ecc-4195-8482-e954129ddf70 ro single
initrd /boot/initrd.img-2.6.28-13-generic

title Ubuntu 9.04, kernel 2.6.28-11-generic
uuid f2499860-0ecc-4195-8482-e954129ddf70
kernel /boot/vmlinuz-2.6.28-11-generic root=UUID=f2499860-0ecc-4195-8482-e954129ddf70 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 f2499860-0ecc-4195-8482-e954129ddf70
kernel /boot/vmlinuz-2.6.28-11-generic root=UUID=f2499860-0ecc-4195-8482-e954129ddf70 ro single
initrd /boot/initrd.img-2.6.28-11-generic

title Ubuntu 9.04, memtest86+
uuid f2499860-0ecc-4195-8482-e954129ddf70
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 Windows NT/2000/XP
rootnoverify (hd0,0)
savedefault
makeactive
chainloader +1


# This entry automatically added by the Debian installer for a non-linux OS
# on /dev/sda2
title Windows Vista (loader)
rootnoverify (hd0,1)
savedefault
makeactive
chainloader +1

OK merci pour le timeout, ca marche nickel.
En ce qui concerne xp et vista, en fait il s'avère que XP n'est en fait qu'un utilitaire de restauration (il était présent avant que je ne fasse quoique ce soit)

en fait j'arrive pas a enregistrer les modifications apportées au menu.lst....

Nickel! merci beaucoup Geis007!