“I had ubuntu server running until i changed the fstab file” AFAIK manually changing fstab is not involved during the installation. Did you install successfully and then changed fstab? Why and how? Please clarify.

Yes i installed ubuntu successfully. after i changed fstab and rebooted, ubuntu wasn't able to boot. I formatted the disk and tried to reinstall ubuntu

Thank you for the details, it’s clearer now. I hadn’t understood that you are trying to re-install Ubuntu. I’ve edited the question for you to get meaningful reactions. I also found a related topic on another Stack Exchange site: unix.stackexchange.com/questions/348806/…

Which version of Ubuntu Server was running (18.04 LTS or an earlier version)? Which installer did you use (name of the iso-file)?

The version i'm using is: ubuntu-18.04-live-server-amd64

Thank you, i will try the answer from Stack Exchange

What is different (in the computer settings or hardware) between the first time when you succeeded in installing Ubuntu Server from ubuntu-18.04-live-server-amd64 and this time, when you get this failure? For example, how did you format the drive? Did you create a new partition table (in that case what partition table, MSDOS or GPT)?

I formatted the drive using a Windows 10 USB. nothing really changed in the hardware and I have tried resetting the uefi to the default settings. I'm able to install windows normally

when i add acpi= off and press Ctrl+X it boots to a black screen with a _ in the upper left corner

Have you got a computer (or can borrow) where you can run linux now? And have you got two USB pendrives (or can borrow). It would be enough to boot from a USB pendrive with linux. Then you can create a live system (for example with Lubuntu with a light-weight desktop environment) and use gparted and create an MSDOS partition table (or GPT) in the drive where you want to install Ubuntu Server.

Is it black also when you boot from the USB install drive, or only from the installed system?

It is black when i run the ubuntu installer from the usb drive, add acpi=off en press Ctrl+X.

Can you run some other live Ubuntu iso file in that computer. I understand that the hardware is new with Intel i3 generation 8 CPU, so I think it is best to try a new version of Ubuntu, maybe the Ubuntu mini.iso or Lubuntu desktop or alternate iso file. Just to try what works and what does not work. (My newest computer has an Intel i3 generation 6 CPU, so I cannot test really new hardware in my compters.)

I tried Lubuntu and when i press install lubuntu it gives the exact same screen as seen above

Maybe you can try with some boot options, for example nomodeset.

I tried nomodeset and acpi=off and with both of them when I press Ctrl+X they give the black screen with the dash _