Restore GRUB after Windows installation
Ubuntu installation on a system which already has other operating systems is simple. Ubuntu will automatically detect other operating systems already installed on the computer and enable booting into them from the grub boot menu. However if you install Windows on a system which already has Ubuntu installed on a partition other than the partition on to which you install windows then you will inevitably lose the option to boot into the Ubuntu installation. There is a simple way to rectify this issue.
Boot into Ubuntu using the Ubuntu Live CD
Open Gedit and copy the following code into it
mount /dev/<hda6> /mnt/hdd
grub-install --root-directory=/mnt/hdd /dev/<hda>
Change <hda6> to whichever partition your /boot resides
Change <hda> to whichever harddisk you want to install grub to
Open a terminal, copy the code from GEdit and paste into the terminal
Presto! You are done
If you have any questions please feel free to Contact Us. You can also call us at +91-471-4063818 to get further assistance. If you can bring your PC to our office we will fix this for free else call us we will come over to your place and fix this issue for a nominal service charge.