How to remove an OS from Grub menu

hi Mrlopes,
you should be able to edit your /boot/grub/menu.lst to remark out the os you dont want.

However, I believe what is happening is that grub is now listing multiple kernels. Can you please post your /boot/grub/menu.lst file? Thanks.

Thanks for your reply
Here is what you asked...

# 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 3

## 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=e997f855-6568-4d41-950c-4b5ca2d0e24a ro

## default grub root device
## e.g. groot=(hd0,0)
# groot=(hd0,0)

## 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

## 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 8.10, kernel 2.6.27-13-generic
root (hd0,0)
kernel /boot/vmlinuz-2.6.27-13-generic root=UUID=e997f855-6568-4d41-950c-4b5ca2d0e24a ro quiet splash
initrd /boot/initrd.img-2.6.27-13-generic
quiet

title Ubuntu 8.10, kernel 2.6.27-13-generic (recovery mode)
root (hd0,0)
kernel /boot/vmlinuz-2.6.27-13-generic root=UUID=e997f855-6568-4d41-950c-4b5ca2d0e24a ro single
initrd /boot/initrd.img-2.6.27-13-generic

title Ubuntu 8.10, kernel 2.6.27-12-generic
root (hd0,0)
kernel /boot/vmlinuz-2.6.27-12-generic root=UUID=e997f855-6568-4d41-950c-4b5ca2d0e24a ro quiet splash
initrd /boot/initrd.img-2.6.27-12-generic
quiet

title Ubuntu 8.10, kernel 2.6.27-12-generic (recovery mode)
root (hd0,0)
kernel /boot/vmlinuz-2.6.27-12-generic root=UUID=e997f855-6568-4d41-950c-4b5ca2d0e24a ro single
initrd /boot/initrd.img-2.6.27-12-generic

title Ubuntu 8.10, kernel 2.6.27-11-generic
root (hd0,0)
kernel /boot/vmlinuz-2.6.27-11-generic root=UUID=e997f855-6568-4d41-950c-4b5ca2d0e24a ro quiet splash
initrd /boot/initrd.img-2.6.27-11-generic
quiet

title Ubuntu 8.10, kernel 2.6.27-11-generic (recovery mode)
root (hd0,0)
kernel /boot/vmlinuz-2.6.27-11-generic root=UUID=e997f855-6568-4d41-950c-4b5ca2d0e24a ro single
initrd /boot/initrd.img-2.6.27-11-generic

title Ubuntu 8.10, kernel 2.6.27-10-generic
root (hd0,0)
kernel /boot/vmlinuz-2.6.27-10-generic root=UUID=e997f855-6568-4d41-950c-4b5ca2d0e24a ro quiet splash
initrd /boot/initrd.img-2.6.27-10-generic
quiet

title Ubuntu 8.10, kernel 2.6.27-10-generic (recovery mode)
root (hd0,0)
kernel /boot/vmlinuz-2.6.27-10-generic root=UUID=e997f855-6568-4d41-950c-4b5ca2d0e24a ro single
initrd /boot/initrd.img-2.6.27-10-generic

title Ubuntu 8.10, kernel 2.6.27-8-generic
root (hd0,0)
kernel /boot/vmlinuz-2.6.27-8-generic root=UUID=e997f855-6568-4d41-950c-4b5ca2d0e24a ro quiet splash
initrd /boot/initrd.img-2.6.27-8-generic
quiet

title Ubuntu 8.10, kernel 2.6.27-8-generic (recovery mode)
root (hd0,0)
kernel /boot/vmlinuz-2.6.27-8-generic root=UUID=e997f855-6568-4d41-950c-4b5ca2d0e24a ro single
initrd /boot/initrd.img-2.6.27-8-generic

title Ubuntu 8.10, kernel 2.6.27-7-generic
root (hd0,0)
kernel /boot/vmlinuz-2.6.27-7-generic root=UUID=e997f855-6568-4d41-950c-4b5ca2d0e24a ro quiet splash
initrd /boot/initrd.img-2.6.27-7-generic
quiet

title Ubuntu 8.10, kernel 2.6.27-7-generic (recovery mode)
root (hd0,0)
kernel /boot/vmlinuz-2.6.27-7-generic root=UUID=e997f855-6568-4d41-950c-4b5ca2d0e24a ro single
initrd /boot/initrd.img-2.6.27-7-generic

title Ubuntu 8.10, kernel 2.6.22-15-generic
root (hd0,0)
kernel /boot/vmlinuz-2.6.22-15-generic root=UUID=e997f855-6568-4d41-950c-4b5ca2d0e24a ro quiet splash
initrd /boot/initrd.img-2.6.22-15-generic
quiet

title Ubuntu 8.10, kernel 2.6.22-15-generic (recovery mode)
root (hd0,0)
kernel /boot/vmlinuz-2.6.22-15-generic root=UUID=e997f855-6568-4d41-950c-4b5ca2d0e24a ro single
initrd /boot/initrd.img-2.6.22-15-generic

title Ubuntu 8.10, memtest86+
root (hd0,0)
kernel /boot/memtest86+.bin
quiet

### END DEBIAN AUTOMAGIC KERNELS LIST

Menu.lst shows only Ubuntu images, what do you mean by removing OS?

Bootmenu is hidden, note this lines in menu.lst:
## hiddenmenu
# Hides the menu by default (press ESC to see the menu)
hiddenmenu

##Default option is:
#hiddenmenu

You can always try to boot from a previous kernel image,
e.g.
title Ubuntu 8.10, kernel 2.6.27-12-generic

if the latest one
kernel 2.6.27-13-generic
doesn't work.

Or in either recovery mode.

Any time a kernel update comes in, older kernel images will not be removed automatically, because of the usefulness of still having one if booting fails with the new image.

To remove kernel images please use Synaptic and search for 'linux-image'.
You'll find installed images (marked with different colour) which are also listed in the menu.lst
Consider to remove 'older' images to regain also space in the 'root' filesystem, which might save trouble one day. After a removal with Synaptic GRUB will update automatically the menu.lst.
Consider to remove carefully, at best keep the latest three images.

In any case backup menu.lst before changing anything:
cp /boot/grub/menu.lst /boot/grub/menu.lst.backup

If you prefer to remove or comment the entries manually in menu.lst, update when finished with:
sudo update-grub

If only, e.g. three images, should appear in the boot menu, you can change this line in menu.lst:
from
# howmany=all
to
#howmany=3

In any case other kernel images will still remain on the system and have to be removed manually.

Many many thanks...