grub not showing when installed on a separate boot partition

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http://askubuntu.com – I just installed ubuntu 12.04 using a different partition for the /boot (I don't know why exactly I did this, I remembered reading somewhere on the web about this). The thing is that after this operation, the grub is not showing at boot, so the computer is loaded directly into windows. The partitions available on my hdd look something like this: ubuntu partition -> mounted / swap area partition ubuntu boot partition -> mounted /boot windows partiton windows system reserved partition (was created automatically) What should I do in order to have grub showing at boot ? I searched for this kin (HowTos)