I have two hard disks – one a 1TB and the other a 250 GB. I installed the OSes in the following order: Windows 7 on the first hard disk (1 TB) After that Kubuntu 12.04 on a partition (/dev/sdb7) on the second hard disk (250 GB) The second drive also contains an NTFS partition. Now, kubuntu's bootloader was installed on the second hard drive's MBR (and successfully detected Windows 7). So, whenever I wanted to load Windows I used to select the first hard disk from the BIOS boot menu and the second hard disk whenever I wanted to load kubuntu. I know I could have set the second hard disk as the default drive, still I prefered this method. The problem started when I installed Linux Mint 13 on the second hard disk (/dev/sdb3) and overwrote kubuntu's original MBR. Now, the GRUB just detects Mint and Windows. The MBR on the 1 TB hard disk is untouched. Is there a way I can modify the MBR on the second hard disk now so that it will show kubuntu and Mint both?