Partitioning – How to Install Ubuntu Without Formatting Any Partitions

You can use Gparted (available in the Ubuntu Software Centre) to resize the 2TB down in 200GB and format those 200GB as FAT.

That process does not require you to format the previous NTFS partition, but its always a risk. There is no 100% safe process for that and a backup of your data is always the most responsible thing to do.

Instructions on how to install and use Gparted are here: How to resize partitions?

Just open the program, locate your hard disk, right click on the partition and select resize/move, give it some room on the right up to the amount you need and create a new partition on the new free space. After you applied the changes you will have 2 partitions on your disk: the old one containing your data, and a new formatted 200GB FAT32 partition.

Select something else then click on the disk that you want to install ubuntu then change its mount point to "/" root. Format that partition with ext4. Thats it! complete the installation.