Dual Booting with Windows 10 - Ubuntu will see Windows 10 as FreeDOS during installation?

Question

So, I bought a Lenovo Laptop a while ago and installed Windows 10 on a partition I created (as I remember) - I don't remember anything about uninstalling FreeDOS or something in that category.

Now here is my current setup of partitions: Screenshot of my partitions

What is that marked partition in the screenshot?

I wanted to install Ubuntu beside windows but got: "Install Ubuntu Alongside FreeDOS" instead of getting "Install Ubuntu Alongside Windows 10" as expected in the setup wizard of Ubuntu.

I just don't want to lose Windows 10 files after installed Ubuntu, what should I do next?
How do I uninstall FreeDOS so I end up with exactly two OSes on my machine?

PS: I tried installing elementaryOS a while ago and partitioned EXT4 and SWAP partitions for it, and ended up with GRUB not seeing Windows 10, instead, giving me the options of booting to either elementaryOS or FreeDOS, so I had to go through the process of reinstalling Windows 10, and all the drivers and updates again (which I don't want to go through again).

Answer 1

The FAT32 partition of 1000 MB looks very much like the EFI system partition, described as:

The EFI system partition (ESP) is a partition on a data storage device (usually a hard disk drive or solid-state drive) that is used by computers adhering to the Unified Extensible Firmware Interface (UEFI). When a computer is booted, UEFI firmware loads files stored on the ESP to start installed operating systems and various utilities.

An ESP contains the boot loaders or kernel images for all installed operating systems (which are contained in other partitions), device driver files for hardware devices present in a computer and used by the firmware at boot time, system utility programs that are intended to be run before an operating system is booted, and data files such as error logs.

This is an essential partition which shouldn't be touched, or you risk making the computer unbootable.

For the message of "Install Ubuntu Alongside FreeDOS", in my opinion this just means that Ubuntu has misidentified the Windows partition. By default it won't find Windows on an existing partition. Just insure that the Ubuntu partition is indeed being taken from the unallocated space.