4. Installation Summary: But before it starts the actual installation, it will let you know what it will do in the installation summary step. You can see that two partitions will be created, and because they will be created as logical partitions, the device numbers will be sda5 and sda6. The former is the root partition, while the latter is the Swap space. If you want to see where GRUB will be installed, click the Advanced button. When you’ve satisfied your curiosity, click the Install button.
5. Install GRUB: After the installation, and assuming it was successful, rebooting the computer will drop you into your new BackTrack 5 R3 installation. As with the live desktop, it will drop you to a console. Now, you need to login. The default username is root, and the password is toor. Once you are logged in, you may start the graphical desktop by typing startx.
The task at this step is to install GRUB in the root partition. You need to launch a shell terminal to do that. There’s an icon for it on the top panel. If you do not remember the device number of the root partition, type df -h to see a listing of the partitions on the system. Now that you know what it is, type grub-install /dev/sda5 to install GRUB in its first sector.
After typing that command and pressing the Enter or Return key, the system will inform you that it’s a bad idea to install GRUB anywhere but in the MBR, and will refuse to execute the command. But you can force it. And that’s exactly what you’ll need to do.
6. Force-install GRUB: To install GRUB by force in the root partition, give the last command the – -force switch, so that it becomes grub-install – -force /dev/sda5.
If executed successfully, there should be no errors, which means that you now have GRUB installed in the MBR and in the root partition of BackTrack 5. Reboot the computer. Since you are still at the command line, you can reboot by typing shutdown -r now. At the boot menu, select the Windows 7 entry to boot into Windows 7.
7. Install EasyBCD: Once in Windows 7, you now need to reinstall Windows 7′s boot loader in the MBR, which is the same thing as wiping GRUB from that location. Windows has a command-line for doing it, but EasyBCD is a free, graphical application that makes it very easy. You may download it from here. Install and start it. This is the main interface. Click the BCD Deployment tab.
8. Reinstall Windows Boot Loader in the MBR: In the BCD Deployment, select the highlighted option, then click on the Write MBR button. After this, exit EasyBCD and reboot the computer, just to make sure that you can reboot into Windows. Note: You will not be able to boot into BackTrack 5, because Windows is now in charge and its boot loader is not ware that Windows 7 is sharing the HDD with another operating system.
9. Add Entry for BackTrack 5: If you managed to reboot into Windows 7, start EasyBCD again, then click on the Add New Entry tab. Select the highlighted options, then click on Add Entry.
10. Preview Windows 7′s Boot Menu: You can see the entries that will be in the boot menu from the Edit Boot Menu tab. You may now close EasyBCD, reboot the computer and test to see if you can boot into both operating systems.
This method worked for me on first try. If you followed the steps as given in this tutorial, it should work for you too.