VirtualBox - openSUSE installation
Launch VirtualBox.
For instructions to download openSUSE Leap 15.4 Desktop see openSUSE Leap 15.4
Step 1 - Create a new virtual machine
Select the New icon.
Under the dropdown heading Name and Operating System, provide a name for the new virtual machine e.g. openSUSE.
In the ISO Image: input box select the downloaded openSUSE ISO image on your machine.
Select the Hardware dropdown and set the memory size. Avoid going beyond the green section.
Also select the number of processors.
Select the Hard Disk dropdown and set the size of the Hard Disk.
Click the Finish button.
You will be returned to the VirtualBox Manager, now displaying the newly created machine.
Step 2 - Adjust the machine settings
With the newly created machine selected, select Settings.
Select System.
Ensure the Motherboard tab is selected.
In the centre, untick Floppy and click on the down arrow to move Floppy to below Hard Disk.
Ensure Optical is now at the top of the list followed by Hard Disk.
Click the OK button.
Step 3 - Installing openSUSE Leap 15.2
With the new openSUSE machine selected, click the green Start arrow. Use the Down Arrow key to select Installation and press the enter key.
Allow the installation to initialise.

Select the language.
Click the Yes button to activate online repositories.
Click on the Next button to accept the list of repositories.
Select the Desktop preference and click the Next button.
Click the Next button to accept the suggested partitioning.
Select the clock and time zone settings and click the Next button.
Enter the user credentials and click the Next button.
Click the Install button.
To confirm the installation details click the Install button.
The virtual machine is ready to use, sign in to continue.
When openSUSE is powered off, the ISO CD/DVD can be removed from the machine.
With the openSUSE machine selected in the left pane of VirtualBox Manager, select Settings.
In the left pane select Storage and in the centre pane select openSUSE-Leap-15.2-DVD-x86_64.iso.
Select the CD/DVD icon and select Remove Disk from Virtual Drive.
Step 5 - Change boot order
Alter the boot order so that the Hard Disk is set to boot first.
From the VirtualBox Manager select Settings.
Select System.
Select the Hard Disk in the list and by using the arrow buttons, move it to the top of the list.
To install Virtualbox Guest Additions see Virtualbox Guest Additions - openSUSE