Question: I booted my computer today and found Ubuntu 16 and its interface is getting loaded although it displays Ubuntu 20 everywhere. The first login screen is also that of Ubuntu 20. How do I change it back to Ubuntu 20 interface.[![screenshot](https://i.stack.imgur.com/o95BZ.jpg)](https://i.stack.imgur.com/o95BZ.jpg)

Extra information:-

history of commands that I ran-
[![history](https://i.stack.imgur.com/Wzkcu.png)](https://i.stack.imgur.com/Wzkcu.png)

Basically what I did was- install timeshift, create partition table in flash drive, took backup in it, reduced startup applications (only microsoft teams app), upgrade from Ubuntu 18.04 to 20.04 and download ampgpu graphics driver. The computer still worked fine after restarting multiple times.
This morning I tried to access the grub menu by pressing shift multiple times. Didn't open GRUB, but I was greeted with this issue.

Answer: 
As of late, there have been numerous complaints about unetbootin not working. I do not know the specifics, but the end result is usually something like 'no operating system found'.

There is a solution. It's to use a different program. My personal favorite is [Balena Echer](https://www.balena.io/etcher/).

You might also consider [Mkusb](https://help.ubuntu.com/community/mkusb). There's [MultiBootUSB](http://multibootusb.org/) that is more aimed at multiple ISOs on one USB. The list goes on and you can [search for alternatives](https://alternativeto.net/software/unetbootin/?platform=linux). If you're using Windows, there are even more choices.
Installers that Work for FreeDOS
--------------------------------

I tried a few popular OS installers with FreeDOS FD12FULL.img file. FreeDOS 1.2 was the latest version that I could find on the freedos.org site.

I formatted the USB flash drive as FAT32 and used the various tools to create an installer on the drive, then I booted the drives and used the FreeDOS installer to install on another flash drive.

The installer tools that worked for me were Unetbootin (Windows & Linux), Etcher (W&L), Rufus (W), Win32DiskImager (W), mkusb Live (L), SDC (L) and Gnome-Disks (L).

YUMI (W), Universal (W) and Ventoy (W&L) did not work with the FreeDOS image file.