I need to reinstall my GRUB since I cannot boot windows 8 anymore (something happened with my installation of Ubuntu). I want to follow this advice - Boot error > no such device: grub rescue in order to re-install the grub but I made the stupid mistake of allocating half of the size of the partition to windows and half to Ubuntu lol. So now I need to know on which partition I have Linux could someone help me out ? Thanks. Here is the partition list

   Device Boot      Start         End      Blocks   Id  System

/dev/sda1   *        2048      718847      358400    7  HPFS/NTFS/exFAT
/dev/sda2          718848  1025779711   512530432    7  HPFS/NTFS/exFAT
/dev/sda3      1025779712  1851121663   412670976    7  HPFS/NTFS/exFAT
/dev/sda4      1851121664  1953521663    51200000    f  W95 Ext'd (LBA)
/dev/sda5      1851123712  1953521663    51198976    7  HPFS/NTFS/exFAT


sorry, I had a crash Here is another list I get :

   Device Boot      Start         End      Blocks   Id  System

/dev/sdb1            2048   923381759   461689856    7  HPFS/NTFS/exFAT
/dev/sdb2       923381760  1438451711   257534976    7  HPFS/NTFS/exFAT
/dev/sdb3      1438453758  1953523711   257534977    5  Extended

Partition 3 does not start on physical sector boundary.

/dev/sdb5      1920051200  1953523711    16736256   82  Linux swap / Solaris
/dev/sdb6      1886576640  1920040959    16732160   82  Linux swap / Solaris
/dev/sdb7      1853102080  1886560255    16729088   82  Linux swap / Solaris
/dev/sdb8      1438453760  1819625471   190585856   83  Linux
/dev/sdb9      1819627520  1853097983    16735232   82  Linux swap / Solaris


I want to boot into windows actually

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According to your partition list, there is NO Ubuntu partition. –  Mitch Oct 1 '13 at 7:29
well I installed it alongside windows but now I can't boot windows. It says error unknown device - some numbers then grub rescue. Can you help me please ? –  yamakoto Oct 1 '13 at 7:30
Here is another list I get –  yamakoto Oct 1 '13 at 7:45
@yamakoto - you appear to have multiple accounts. Please register one of these accounts. Then click the contact-us link at the bottom of this page to request your other accounts are merged. Once done, you'll be able to re-edit your question with further details. Thanks. –  fossfreedom Oct 1 '13 at 8:56

Boot the Live Sytem from your installation medium. Mount the partitions and search for your Ubuntu (should be easy to find, directories like etc, home, usr, root in the root directory of the partition)