Create bootable media - OnTheKnows/A GitHub Wiki

https://www.reddit.com/r/WindowsServer/comments/asootr/how_to_create_a_bootable_usb_for_windows_server/ To create a bootable USB as a Windows Server 2019 installer, you need to prepare Windows Server 2019 ISO image files, a USB drive that is at least 8GB. Then you can open Diskpart tool to finish such task.

Step 1. Insert an empty USB drive to your computer.

Step 2. Click “Start” button, input “cmd” in the search box and press Enter, right click the program and choose “Run as Administrator” option.

Step 3. In the elevated Command Promtp window, type “diskpart” and press “Enter” to start the DiskPart tool. Next type and execute all the below commands one by one.

list disk

select disk #

clean

create partition primary

select partition 1

format fs=ntfs quick (if you plan to create UEFI bootable USB using Diskpart, type “format fs=fat32 quick” instead to format it into FAT32 file system)

active

Then type “exit” and press “enter” to leave diskpart, but do not close Command Prompt since we just finish creating a bootable USB flash drive. Now we need to take other steps to copy Windows Server 2019 installation files to the created bootable USB drive.

Step 4. Open the Windows Server 2019 installation files and copy them to the USB stick by running the command: xcopy d:*. * /s/e/f e:\

Note:(d:\ is refer to your windows installer drive letter, and the e:\ is refer to your USB flash drive.

Step 5. Finally, write a bootloader to your USB stick using command: D:\Boot\Bootsect /NT60 E: /force /mbr

When everything is done, you can use this USB drive to boot and install Windows Server 2019.

If you don't want to run such complicated commands, you can use a third-party tool to install Windows Server onto USB drive for installing operating system more easily.