Partition number three will be for Swap. This is disk space that the system may use as virtual memory. The default is about 2 GB, but you can go higher than that. It all depends on how much memory is installed. See recommended disk space for Swap for help in deciding how much (disk space) to allocate. Be sure to select “swap area” from the “Use as” dropdown menu before clicking OK.
The last partition will be mounted at /home. This is where your home directory and that of every user account you create on the system will be located. How much disk space you allocate to it will, of course, depend on what is available. The file system is ext4. OK.
With all the partitions in place, the last task in this step, before moving on to the next one, is to select where the boot loader will be installed. By default, the installer installs it in the Master Boot Record (MBR) of disk number 1. But the best location is in the MBR of disk number 2, where Ubuntu 11.10 will be installed. So change the Device for boot loader installation from sda to sdb.
Make sure that sdb is selected from the boot device menu before clicking Install Now. If you neglect to do this, GRUB will be installed in the MBR of sda, overwriting Windows boot loader. After you have made the change, click Install Now.
After installation, the computer will boot into Windows 7, unless you change the boot device from the BIOS boot menu. The final step is to add an entry in Windows’ boot menu for Ubuntu 11.10. You achieve that by messing with the Windows Boot Configuration Data (BCD). There are several programs for doing it, but the best I have found is EasyBCD. The latest edition is free for personal use, but cost about US$25 for commercial use. You may download it from here. Scroll all the way down and look for the link that says “Download free for limited, non-commercial use.” Install it as you would any other Windows application. When you launch EasyBCD, you should see this friendly message from the developers. Make the right choice.
Disclaimer: I have no financial ties to NeoSmart Technologies, the company behind EasyBCD. I recommend it because it is the best I have come across. If you know of any that is better, and free, please post the link in the comments box.
This is the main view of EasyBCD. We cannot do anything here, so click on the Add New Entry tab.
While on the Add New Entry tab, click on the Linux/BSD tab, then select “GRUB2″ from the Type dropdown menu. Edit the Name field to reflect the edition of Ubuntu, then click on Add Entry. Click on Edit Boot Menu to see the result.
From Edit Boot Menu tab, you can see the entries as they will appear on the boot menu and as you will see them every time you (re)boot the computer. When you are satisfied that you have done everything right or done all the right stuff, exit EasyBCD, reboot Windows and see if you can boot into Ubuntu 11.10 from the Windows 7 boot menu. If you followed this guide to the letter, there should be no problems booting into either operating system.Bon Appetit.