Restore Grub after Windows installation
If you install Windows on your computer and you’ve also installed Linux before, you’ll lose your boot settings. That’s because the windows bootloader, which is named NTLDR (NTLoaDeR), replaces your Linux bootloader, which in most cases (for example on Ubuntu Linux) is called Grub.
In order to recover your boot information, so that when you turn on your computer you can choose between different operating systems, you have to recover the Grub. This process is very simple. All you need is an Ubuntu Live CD. Please refer to this article for a detailed step by step guide.
