installing zorin os 12 64 bit

Hello Everyone, I decided to purchase zorin os 12 64 bit dvd. I wish to install zorin to a 1 tb Seagate external harddrive, with grub installed on the external harddrive, as I do not want
windows boot loader taken over. I wish to keep both systems apart. I have booted the dvd, and clicked install, the Seagate harddrive comes up, but when I click continue it says
no root file system is defined, please correct this from partitioning menu. I have no experience with Linux operating systems, and I really do not know what do to, and I do not want to
make any mistakes that could cause problems with Windows 7. My Asus pc had no trouble picking up that the Seagate external drive is there, and boots easily from usb ports.

Hi read the post by EMK here but the stuff above is also useful but poor grammar (use of txt speak!):

https://www.linux.com/answers/there-way ... an-boot-it

Your external drive should come up as sdb - but could be sdc if you have an optical drive in your machine.

If you want to play totally safe, disconnect the internal hard drive from your machine by just removing the SATA connection to the drive (power cable) to ensure least problems.

In terms of formatting I usually recommend 30 Gb for '/' (root file system) formatted to ext4 and create an extended partition with a 'swap area' equal to the amount of RAM (Memory) you have in your machine at the END of the partition - and whatever is left in front of it make it your '/home' partition formatted to 'ext4' for all your personal stuff and windows applications for wine if you intend using wine.

After installing to your external drive, reconnect your internal hdd and then get yourself a copy of the latest Easy BCD from neo-smart so that you mbr can be updated to have the choice of booting to your Windows Drive or your external drive - look for Matthew Moore's alternative installation video on YouTube on how to do that - I also made one but for dual booting on the same drive on Vimeo.com based on Matthew Moore's example.

Thank you so much for your answers. One strange thing is the Seagate external hard drive is showing as /dev/sda and my internal drive with windows is /dev/sdb. I may go the totally safe
way and disconnect the internal hard drive, as I am becoming a bit nervous about this, due to lack of experience with Linux. Have windows firmly planted in the brain, and how everything
works. I have read the advice from the link above, which is also helpful, and I will download Easy BCD if I can get myself that far. Sorry I do not have any knowledge of this. I will keep working on it, and let you know how it came out. Thank you again.

Hi Matthew Moore's video is here:

https://youtube.com/watch?v=xlTgaWs9BD0

my video:


https://vimeo.com/110085401