Dual-boot Windows 7/Ubuntu 10.10

Bonjour,
Alors, j'ai un problème de multiboot avec Windows 7 et Ubuntu 10.10 64 bits. Je n'arrive qu'a booter sur Ubuntu et le menu de Grub ne s'affiche pas. Je ne sais que faire. Je vous donne le résultat du sudo fdisk :

Disk /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xc3ea0791

Device Boot Start End Blocks Id System
/dev/sda1 * 1 19458 156289024 7 HPFS/NTFS

Disk /dev/sdb: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xc3ea0793

Device Boot Start End Blocks Id System
/dev/sdb1 * 1 7291 58556877+ 7 HPFS/NTFS
/dev/sdb2 7291 9730 19592193 5 Extended
/dev/sdb5 7291 9608 18615296 83 Linux
/dev/sdb6 9608 9730 975872 82 Linux swap / Solaris

Le sda1 ne contient pas d'OS, seulement les Documents de Windows, il est le premier disque dur à amorcer.
Et pour ceux qui veulent le résultat du bootinfoscript :

Boot Info Script 0.55 dated February 15th, 2010

============================= Boot Info Summary: ==============================

=> Grub 2 is installed in the MBR of /dev/sda and looks on the same drive in
partition #5 for (,msdos5)/boot/grub.
=> Grub 0.97 is installed in the MBR of /dev/sdb and looks on the same drive
in partition #5 for /boot/grub/stage2 and /boot/grub/menu.lst.

sda1: _________________________________________________________________________

File system: ntfs
Boot sector type: Windows Vista/7
Boot sector info: No errors found in the Boot Parameter Block.
Operating System:
Boot files/dirs: /bootmgr /Boot/BCD /boot/grub/core.img

sdb1: _________________________________________________________________________

File system: ntfs
Boot sector type: Windows Vista/7
Boot sector info: No errors found in the Boot Parameter Block.
Operating System: Windows 7
Boot files/dirs: /bootmgr /Boot/BCD /Windows/System32/winload.exe
/ntdetect.com

sdb2: _________________________________________________________________________

File system: Extended Partition
Boot sector type: -
Boot sector info:

sdb5: _________________________________________________________________________

File system: ext3
Boot sector type: -
Boot sector info:
Operating System: Ubuntu 10.10
Boot files/dirs: /boot/grub/grub.cfg /etc/fstab /boot/grub/core.img

sdb6: _________________________________________________________________________

File system: swap
Boot sector type: -
Boot sector info:

=========================== Drive/Partition Info: =============================

Drive: sda ___________________ _____________________________________________________

Disk /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders, total 312581808 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

Partition Boot Start End Size Id System

/dev/sda1 * 2,048 312,580,095 312,578,048 7 HPFS/NTFS


Drive: sdb ___________________ _____________________________________________________

Disk /dev/sdb: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders, total 156301488 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

Partition Boot Start End Size Id System

/dev/sdb1 * 2,048 117,115,802 117,113,755 7 HPFS/NTFS
/dev/sdb2 117,116,926 156,301,311 39,184,386 5 Extended
/dev/sdb5 117,116,928 154,347,519 37,230,592 83 Linux
/dev/sdb6 154,349,568 156,301,311 1,951,744 82 Linux swap / Solaris


blkid -c /dev/null: ____________________________________________________________

Device UUID TYPE LABEL

/dev/loop0 squashfs
/dev/sda1 3AD80F2B3E2C7FBC ntfs
/dev/sda: PTTYPE="dos"
/dev/sdb1 806C7A1D6C7A0DE2 ntfs
/dev/sdb2: PTTYPE="dos"
/dev/sdb5 52c665a2-f95d-416d-be44-a73d61c582c7 ext3
/dev/sdb6 4ac8c8b9-bcaa-4d74-b933-5f6064d23477 swap
/dev/sdb: PTTYPE="dos"
error: /dev/sdc: No medium found
error: /dev/sdd: No medium found
error: /dev/sde: No medium found
error: /dev/sdf: No medium found

============================ "mount | grep ^/dev output: ===========================

Device Mount_Point Type Options

aufs / aufs (rw)
/dev/sr0 /cdrom iso9660 (ro,noatime)
/dev/loop0 /rofs squashfs (ro,noatime)
/dev/sdb5 /mnt ext3 (rw)
/dev /mnt/dev none (rw,bind)
/dev/sda1 /media/3AD80F2B3E2C7FBC fuseblk (rw,nosuid,nodev,allow_other,blksize=4096,default_permissions)


=================== sda1: Location of files loaded by Grub: ===================


??GB: boot/grub/core.img

=========================== sdb5/boot/grub/grub.cfg: ===========================

#
# 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 part_msdos
insmod ext2
set root='(hd1,msdos5)'
search --no-floppy --fs-uuid --set 52c665a2-f95d-416d-be44-a73d61c582c7
if loadfont /usr/share/grub/unicode.pf2 ; then
set gfxmode=1280x1024x32
load_video
insmod gfxterm
fi
terminal_output gfxterm
insmod part_msdos
insmod ext2
set root='(hd1,msdos5)'
search --no-floppy --fs-uuid --set 52c665a2-f95d-416d-be44-a73d61c582c7
set locale_dir=($root)/boot/grub/locale
set lang=fr
insmod gettext
if [ "${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
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
menuentry 'Ubuntu, with Linux 2.6.35-24-generic' --class ubuntu --class gnu-linux --class gnu --class os {
recordfail
insmod part_msdos
insmod ext2
set root='(hd1,msdos5)'
search --no-floppy --fs-uuid --set 52c665a2-f95d-416d-be44-a73d61c582c7
linux /boot/vmlinuz-2.6.35-24-generic root=UUID=52c665a2-f95d-416d-be44-a73d61c582c7 ro quiet splash
initrd /boot/initrd.img-2.6.35-24-generic
}
menuentry 'Ubuntu, with Linux 2.6.35-24-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os {
recordfail
insmod part_msdos
insmod ext2
set root='(hd1,msdos5)'
search --no-floppy --fs-uuid --set 52c665a2-f95d-416d-be44-a73d61c582c7
echo 'Loading Linux 2.6.35-24-generic ...'
linux /boot/vmlinuz-2.6.35-24-generic root=UUID=52c665a2-f95d-416d-be44-a73d61c582c7 ro single
echo 'Loading initial ramdisk ...'
initrd /boot/initrd.img-2.6.35-24-generic
}
menuentry 'Ubuntu, with Linux 2.6.35-22-generic' --class ubuntu --class gnu-linux --class gnu --class os {
recordfail
insmod part_msdos
insmod ext2
set root='(hd1,msdos5)'
search --no-floppy --fs-uuid --set 52c665a2-f95d-416d-be44-a73d61c582c7
linux /boot/vmlinuz-2.6.35-22-generic root=UUID=52c665a2-f95d-416d-be44-a73d61c582c7 ro quiet splash
initrd /boot/initrd.img-2.6.35-22-generic
}
menuentry 'Ubuntu, with Linux 2.6.35-22-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os {
recordfail
insmod part_msdos
insmod ext2
set root='(hd1,msdos5)'
search --no-floppy --fs-uuid --set 52c665a2-f95d-416d-be44-a73d61c582c7
echo 'Loading Linux 2.6.35-22-generic ...'
linux /boot/vmlinuz-2.6.35-22-generic root=UUID=52c665a2-f95d-416d-be44-a73d61c582c7 ro single
echo 'Loading initial ramdisk ...'
initrd /boot/initrd.img-2.6.35-22-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='(hd1,msdos5)'
search --no-floppy --fs-uuid --set 52c665a2-f95d-416d-be44-a73d61c582c7
linux16 /boot/memtest86+.bin
}
menuentry "Memory test (memtest86+, serial console 115200)" {
insmod part_msdos
insmod ext2
set root='(hd1,msdos5)'
search --no-floppy --fs-uuid --set 52c665a2-f95d-416d-be44-a73d61c582c7
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 ###

=============================== sdb5/etc/fstab: ===============================

# /etc/fstab: static file system information.
#
# Use 'blkid -o value -s UUID' to print the universally unique identifier
# for a device; this may be used with UUID= as a more robust way to name
# devices that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc nodev,noexec,nosuid 0 0
# / was on /dev/sdb5 during installation
UUID=52c665a2-f95d-416d-be44-a73d61c582c7 / ext3 errors=remount-ro 0 1
# /windows was on /dev/sda1 during installation
UUID=3AD80F2B3E2C7FBC /windows ntfs defaults,umask=007,gid=46 0 0
# swap was on /dev/sdb6 during installation
UUID=4ac8c8b9-bcaa-4d74-b933-5f6064d23477 none swap sw 0 0
/dev/fd0 /media/floppy0 auto rw,user,noauto,exec,utf8 0 0

=================== sdb5: Location of files loaded by Grub: ===================


66.1GB: boot/grub/core.img
67.1GB: boot/grub/grub.cfg
60.2GB: boot/initrd.img-2.6.35-22-generic
60.4GB: boot/initrd.img-2.6.35-24-generic
60.3GB: boot/vmlinuz-2.6.35-22-generic
60.3GB: boot/vmlinuz-2.6.35-24-generic
60.4GB: initrd.img
60.2GB: initrd.img.old
60.3GB: vmlinuz
60.3GB: vmlinuz.old
=======Devices which don't seem to have a corresponding hard drive==============

sdc sdd sde sdf

Voilà quelqu'un peut m'aider ? Merci