This section will show you how to install Debian OS on a VirtualBox Virtual Machine.

Note: The version we will be using is Debian 12.9.0 codenamed Bookworm.

1. Install Debian version 12.9.0 .iso file from the website www.debian.org.

2. Open Oracle VirtualBox.

3. Click on New.

4. Go under the Name and Operating System tab.

5. Type in the name of the OS which is Debian.

6. At ISO Image, click the drop down menu and click Other.

7. Choose the downloaded Debian .iso file.

8. Go under the Unattended Install tab.

9. Change the username and password to your liking.

10. Go under the Hardware tab. You can change the Base Memory and Processors according to your liking. We will keep it as is.

11. Go under the Hard Disk tab. You can change the hard disk space and other settings. We will keep it as is.

12. Click Finish.

13. Wait for the installation to finish.

14. After installation, it should look like this.

15. Click the username and sign in using the password you set before.

16. Debian OS is now installed successfully!

This section will show you how to enable root account and superuser on Debian.

1. Click on Activities on the top left corner of the screen. You can also press the Windows key as a shortcut.

2. Search for Settings and click on it.

3. On the left pane, scroll down or search for Users and click on it.

4. On the blue bar at the top of the page, click Unlock.

5. Then, enter your user password as the Administrator's password. In my case, it is 1211112299. Once that is done, you should notice that the blue bar is gone.

6. Now press Activities again, and search for Terminal. Click on it.

7. Try using a sudo command and see the results.

sudo whoami

The user megat is not in the sudoers file, we need to change that.

8. Type the following command to go into root. The command may not work without doing steps 1-5.

su root

Notice that megat@vbox changed to root@vbox.

9. Type this command to edit the sudoers file.

sudo visudo /etc/sudoers

10. Search for this line in the file:

# User privilege specification

11. Add the following line to that section of the file. Note that you should replace megat with your username.

megat    ALL=(ALL:ALL) ALL

12. Save the file using Ctrl + O → Enter → Ctrl + X.

13. Type this command to exit root.

exit

14. Type any sudo command again and see the difference.

sudo whoami

Congratulations, your user now has sudo permissions!

Debian 12.9.0 comes preinstalled with GNOME desktop environment. The following steps will show you how to install another desktop environment.

1. In terminal, type sudo tasksel.
   
   Notice that the terminal will look like this.
   
2. We want to install the Xfce desktop environment. Navigate the menu using up and down key. Press space to mark Xfce for installation. Make sure there is the (*) symbol.
3. Press Tab until Ok button is highlighted. Press Enter.
4. Wait for the installation to finish.
   
5. Once its installed, let's switch to the Xfce desktop environment. Click the top right button.
6. Click the power button.
7. Click Log Out…
   
8. Now, click your user.
   
9. Click the Gear icon on the bottom right corner.
10. Click Xfce Session.
11. Login as usual.
12. You have successfully changed your desktop environment!