my computer would reboot automatically after i do a system shutdown

Tell me how exactly you are doing shut-down and by which method you are facing problem!!

when shutting down... i usually go to the launch button on the top far right hand corner, bring the drop down menu up and click on shut down from there. From there the system go into shut down mode and even turn off machine completely, but almost
immediately will reboot again. It work as if you are trying to do a restart except the machine was turn off completely. The only thing I can do from there is to hold the power button manually as the machine tries to reboot... inorder to completely shut it off.

hope this helps... thanks

Ok just double check if it is OS problem.

do one thing one terminal and give command
sudo shutdown -h 0

Lets see if this reboot computer

one more thing you can check .. give command
sudo init 0

see if it reboot or not .. den we will go for another aspect.

cheers

Hi Jeet,

Thanks for showing me... in anycase I execute both commands in the terminal - they both do a complete system and hardware shut down but almost immediately rebooting everything on again... Could it be a corrupt copy of ubuntu 64 that is downloaded????

I don't think it is a corrupt copy ... but question is what went wrong .. if both commands are not solving your problem ... so it can be a OS Error.

Neways Keep this question open (i'll try to check) and again download a fresh Ubuntu and burn as slow as you can. then try again with shutdown.

lets check if media is corrupt.

Cheers

Sorry and
Hi again,

<<Hold on>> do not uninstall your current Ubuntu

Give me out-put of
uname -a
lsb_release -a

and check your Grub.cfg file
if you find these line

"linux /boot/vmlinuz-3.0.0-15-generic-pae root=UUID=99166848-cb15-460b-805d-43bf853d135e ro quiet acpi=force"

Please add "acpi_osi=Linux" after "acpi=force" lets see if it can help.

please let me know

Hi Jeet,
Here is the out put you requested..

privateer@privateer-HP-Compaq-dc5750-Microtower:~$ uname -a
Linux privateer-HP-Compaq-dc5750-Microtower 3.0.0-16-generic #28-Ubuntu SMP Fri Jan 27 17:44:39 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
privateer@privateer-HP-Compaq-dc5750-Microtower:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 11.10
Release: 11.10
Codename: oneiric
privateer@privateer-HP-Compaq-dc5750-Microtower:~$

Below is the Grub.cfg file

I don't see the.. "linux /boot/vmlinuz-3.0.0-15-generic-pae root=UUID=99166848-cb15-460b-805d-43bf853d135e ro quiet acpi=force" you were looking for.

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
  set have_grubenv=true
  load_env
fi
set default="0"
if [ "${prev_saved_entry}" ]; then
  set saved_entry="${prev_saved_entry}"
  save_env saved_entry
  set prev_saved_entry=
  save_env prev_saved_entry
  set boot_once=true
fi

function savedefault {
  if [ -z "${boot_once}" ]; then
    saved_entry="${chosen}"
    save_env saved_entry
  fi
}

function recordfail {
  set recordfail=1
  if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi
}

function load_video {
  insmod vbe
  insmod vga
  insmod video_bochs
  insmod video_cirrus
}

insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set=root 6aadfead-2988-49ff-8d0c-1f1f79128e12
if loadfont /usr/share/grub/unicode.pf2 ; then
  set gfxmode=auto
  load_video
  insmod gfxterm
  insmod part_msdos
  insmod ext2
  set root='(hd0,msdos1)'
  search --no-floppy --fs-uuid --set=root 6aadfead-2988-49ff-8d0c-1f1f79128e12
  set locale_dir=($root)/boot/grub/locale
  set lang=en_US
  insmod gettext
fi
terminal_output gfxterm
if [ "${recordfail}" = 1 ]; then
  set timeout=-1
else
  set timeout=10
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=white/black
set menu_color_highlight=black/light-gray
if background_color 44,0,30; then
  clear
fi
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
if [ ${recordfail} != 1 ]; then
  if [ -e ${prefix}/gfxblacklist.txt ]; then
    if hwmatch ${prefix}/gfxblacklist.txt 3; then
      if [ ${match} = 0 ]; then
        set linux_gfx_mode=keep
      else
        set linux_gfx_mode=text
      fi
    else
      set linux_gfx_mode=text
    fi
  else
    set linux_gfx_mode=keep
  fi
else
  set linux_gfx_mode=text
fi
export linux_gfx_mode
if [ "$linux_gfx_mode" != "text" ]; then load_video; fi
menuentry 'Ubuntu, with Linux 3.0.0-16-generic' --class ubuntu --class gnu-linux --class gnu --class os {
 recordfail
 set gfxpayload=$linux_gfx_mode
 insmod gzio
 insmod part_msdos
 insmod ext2
 set root='(hd0,msdos1)'
 search --no-floppy --fs-uuid --set=root 6aadfead-2988-49ff-8d0c-1f1f79128e12
 linux /boot/vmlinuz-3.0.0-16-generic root=UUID=6aadfead-2988-49ff-8d0c-1f1f79128e12 ro quiet splash vt.handoff=7
 initrd /boot/initrd.img-3.0.0-16-generic
}
menuentry 'Ubuntu, with Linux 3.0.0-16-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os {
 recordfail
 insmod gzio
 insmod part_msdos
 insmod ext2
 set root='(hd0,msdos1)'
 search --no-floppy --fs-uuid --set=root 6aadfead-2988-49ff-8d0c-1f1f79128e12
 echo 'Loading Linux 3.0.0-16-generic ...'
 linux /boot/vmlinuz-3.0.0-16-generic root=UUID=6aadfead-2988-49ff-8d0c-1f1f79128e12 ro recovery nomodeset
 echo 'Loading initial ramdisk ...'
 initrd /boot/initrd.img-3.0.0-16-generic
}
submenu "Previous Linux versions" {
menuentry 'Ubuntu, with Linux 3.0.0-12-generic' --class ubuntu --class gnu-linux --class gnu --class os {
 recordfail
 set gfxpayload=$linux_gfx_mode
 insmod gzio
 insmod part_msdos
 insmod ext2
 set root='(hd0,msdos1)'
 search --no-floppy --fs-uuid --set=root 6aadfead-2988-49ff-8d0c-1f1f79128e12
 linux /boot/vmlinuz-3.0.0-12-generic root=UUID=6aadfead-2988-49ff-8d0c-1f1f79128e12 ro quiet splash vt.handoff=7
 initrd /boot/initrd.img-3.0.0-12-generic
}
menuentry 'Ubuntu, with Linux 3.0.0-12-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os {
 recordfail
 insmod gzio
 insmod part_msdos
 insmod ext2
 set root='(hd0,msdos1)'
 search --no-floppy --fs-uuid --set=root 6aadfead-2988-49ff-8d0c-1f1f79128e12
 echo 'Loading Linux 3.0.0-12-generic ...'
 linux /boot/vmlinuz-3.0.0-12-generic root=UUID=6aadfead-2988-49ff-8d0c-1f1f79128e12 ro recovery nomodeset
 echo 'Loading initial ramdisk ...'
 initrd /boot/initrd.img-3.0.0-12-generic
}
}
### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_linux_xen ###
### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/20_memtest86+ ###
menuentry "Memory test (memtest86+)" {
 insmod part_msdos
 insmod ext2
 set root='(hd0,msdos1)'
 search --no-floppy --fs-uuid --set=root 6aadfead-2988-49ff-8d0c-1f1f79128e12
 linux16 /boot/memtest86+.bin
}
menuentry "Memory test (memtest86+, serial console 115200)" {
 insmod part_msdos
 insmod ext2
 set root='(hd0,msdos1)'
 search --no-floppy --fs-uuid --set=root 6aadfead-2988-49ff-8d0c-1f1f79128e12
 linux16 /boot/memtest86+.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###

### BEGIN /etc/grub.d/30_os-prober ###
if [ "x${timeout}" != "x-1" ]; then
  if keystatus; then
    if keystatus --shift; then
      set timeout=-1
    else
      set timeout=0
    fi
  else
    if sleep --interruptible 3 ; then
      set timeout=0
    fi
  fi
fi
### END /etc/grub.d/30_os-prober ###

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries. Simply type the
# menu entries you want to add after this comment. Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f $prefix/custom.cfg ]; then
  source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###

enter "acpi_osi=Linux" code after this block of your /boot/grub/grub.cfg

"""""""
export linux_gfx_mode
if [ "$linux_gfx_mode" != "text" ]; then load_video; fi
menuentry 'Ubuntu, with Linux 3.0.0-16-generic' --class ubuntu --class gnu-linux --class gnu --class os {
 recordfail
 set gfxpayload=$linux_gfx_mode
 insmod gzio
 insmod part_msdos
 insmod ext2
 set root='(hd0,msdos1)'
 search --no-floppy --fs-uuid --set=root 6aadfead-2988-49ff-8d0c-1f1f79128e12
 linux /boot/vmlinuz-3.0.0-16-generic root=UUID=6aadfead-2988-49ff-8d0c-1f1f79128e12 ro quiet splash vt.handoff=7
 initrd /boot/initrd.img-3.0.0-16-generic

"""""""

one more thing if it would not help you out you can update your grub by "update-grub" command.

please let me know the result hoping it will work for you ...

Cheers.

Have you done this. .sorry I forgot. . Put this code a these lines. Eh are starting from linux. /boot/vmlinuz

Hi Jeet,

I apologize for not being in touch sooner.... In anycase just to be sure (being a noobie) I tried to add the line in the text editor (Grub.cfg) file but it would not let me chane or save the change. Do i do the change in the terminal???

Thank you

Here is something interesting... I haven't got a chance to implement the codes in the grub box... but today I was finally able to add another 3 gb memory to my machine - bought it from ebay. When I reboot the machine and shut it off (completely power down)... it worked perfectly. Of course I have 4 gb of memory now compare to just 1 gb before. Thought that was interesting and weird. Thanks a million again for your help.