How To Install Debian In VBox - A Newbies Guide
Requirements
Personally I recommend that you guys have at least 4 CPU cores and 6GB of ram. Less will work but I like to give at least 3 cores and 4gb of ram to my virtual machines, which would leave 1 core and 2GB of ram left for your host with these minimums.
If you are using a 32bit OS I recommend grabbing 32bit Debian, and if you are running 64bit you will be good with the 64bit iso.
Getting Debian
I recommend grabbing your Debian ISO right away because it will take a little while to download. Downloading while do our VirtualBox stuff just makes for a more efficient use of time. Go ahead and click here to download Debian 9 32bit and click here to download Debian 9 64bit.
Getting And Installing VirtualBox
We need to head over to virtualbox.org and download the program. You can easily start the download from this post by clicking here.
Once we have VirtualBox downloaded, we need to navigate to the folder we downloaded it to and run it. It will ask you a few questions about where to install to just click next on every screen until it is finished installing. It will take only seconds.
Once installed go ahead and open up VirtualBox (should be in your app menu now on Windows). Once you open it you will notice the "New" button at the top left hand side, go ahead and click that. It will ask what name, type and version of OS you will be using. The name is what you are naming your vbox, this can be crypto, test, bicycle or whatever you want. The type will be linux and the OS will be Debian 32bit or 64bit depending on your hardware. After clicking next you will be presented with a screen asking what amount of RAM you would like to allocate. I recommend 3GB or more, but if you have to make due then you have to make due. Select your RAM amount and click next. Here you are asked about storage preferences. The default is selected correctly and you just need to click create. The next screen should have VDI selected as default, which is fine and you can just click next again. The next screen will ask if you want the storage allocated dynamically or if it should be a fixed size. I use fixed size personally but it is up to you. Fixed will automatically take the entire storage amount you specify into reserve, or dynamic will grow as you add files/folders/data etc. Make your decision and click next. Now you will be able to specify the amount of storage you want to allocate and I recommend 30-50GB here just to be safe and have plenty of room. Linux is tiny and will not use much of that for OS purposes. Once finished click create and we are almost ready to install.
The next thing we need to do is allocate more CPU to this thing because it will use 1 core by default, which is nothing. You should be back at the main VirtualBox screen now and your new machine should be listed on the left hand side. Right click your new machine and click the settings option. On the left side of the screen you will see the system category, select this and then when the options open select the processor tab. You should now be able to use a slider or a text box to change the amount of cores we are using. If you are on a 4 core machine use 3 and if you are on a dual-core machine use only 1 (this will be somewhat slow). Click OK once you are finished and your new machine is all done!
Installing Debian
Now we get into the fun part which begins by clicking start with your newly created machine highlighted. Once the machine opens it will ask you for an ISO to use. Click the folder icon to browse for your Debian 9 download. Make sure it is done downloading or this will not work. It takes 30 mins to an hour depending so just double check. If the ISO is fully downloaded select it and click start.
The first screen of the install will ask you how to start. You will select graphical install and hit enter. Now you need to enter your language and click continue. You will be asked for your country now. Once you have found yours, click continue. The last locale screen will ask you for your keyboard mapping settings, so pick the one that works for you and click continue.
The install will auto-detect your cd-rom (which is not really there) and then start to load up the data and configure your network. You will be asked to enter a hostname on the next screen. Your hostname is the name your network recognizes your computer as. You can name this whatever you would like and then click continue. You will now be asked for a domain name. Unless you know what you want to enter here leave it as default and click continue.
The next part of the configuration is to setup users. You will first be asked for a root password. Your root account is the same as your admin account on Windows. You have full privs. Most people do not use their root account for daily use however, so once you enter this password it will ask you to create your normal user. Enter a username, click continue and then enter a nice and secure password. I recommend 16+ characters personally.
Once finished with users, your clock will be automatically configured and you will be asked for your timezone. Enter your appropriate answer and click continue.
Next we will configure the storage (hard drive). Since this is a beginner tutorial I want to you be secure but I also want it to be easy. The easiest way to configure Full Disk Encryption is to simply select "Guided - user entire disk and setup encrypted LVM". Select this option and continue. The next screen should only have one drive listed as default, the one you just made (sda). Select this and continue. On the next screen you want to make sure to select "Separate /home partition" and click continue. You will now have to verify that you sure, select yes and click continue. It might take a little while for the drives to be wiped and ready for Full Disk Encryption so take a break now.
Alright so the disk has finished wiping and now it is time to setup a secure password for the encryption. I recommend 16-32 characters non-sequential, upper/lower case and use symbols. I know you hate me, but so will the people trying to crack that password. Once you have input your passphrase, click continue. The last screen should be all good to go, just make sure you have selected "Finish partitioning and write changes to disk" and click continue. You will be asked to confirm on the next screen, select yes and continue. Your drives will be configured now and the base system will install itself and should not take too long. Once done a screen will pop up asking you about more cd's/dvd's. Keep no selected and continue.
Now the package manager will ask us for our location so it can find us some fast mirrors to download from. Select your country and pick a mirror. I like to use mirrors.kernel.org personally but mileage may vary. Click continue and pay no attention to the next screen asking about proxies, just continue. A screen will pop up asking about a machine survey, keep no selected and click continue. Finally you will be presented with the software install screen. I recommend ONLY ticking "Debian desktop environment" and "Standard system utilities". Once this is correct, click continue. Now about 1200-1300 packages will download automatically, this is the OS itself. It might take a while to download and finish installing so this could be another break if you feel you need one.
Once it has finished installing everything it will ask if you would like to install grub to your hdd, select yes and continue.
Select your hard drive (it will be the only thing in the list aside from "enter manually"). It is important to make sure you actually have the sda drive selected here or it will NOT boot when we reboot the machine. So once /dev/sda is selected, click continue. The install will finish up and you will be asked to hit continue to reboot. We are done with the install!
Update and Upgrade
When the machine reboots you will be prompted for your encryption passphrase, input it and hit enter. Now the machine will boot and the default user will be your normal user, however we need to do something with root first. Click "not listed" and then enter root as the username followed by the password you created for your root account. Once you are in your root account you will need to click the activities tab in the top left of the screen. When the drop down opens and the search bar pops up type in "terminal" and a little black terminal icon will appear, click this. In the terminal type the following.
apt-get update && sudo apt-get upgrade
You will need to enter your root password again and hit enter (it will look like you are not typing, you are though). When asked to confirm the upgrade, type the letter y and hit enter. Now once all that finishes you need to type the following.
apt-get install sudo
Once sudo is installed we need to add our normal user to the list. I like doing it the old-school way. In the terminal type this.
nano /etc/sudoers
When the list opens it will look weird but that is ok, just find the line that says root: ALL=(ALL:ALL) ALL. Directly below that line you want to create an exact copy of that line, but instead of root use your normal username. Once it looks exactly the same, but with your name, hit control+x to exit, y to save and hit enter. Now we can reboot or logout and login as our normal user which will have sudo powers now. This means you can make system changes and all the fun stuff by prefixing commands with "sudo". Lets get our firewall setup and we are all done with this one guys!
Basic Security
Alright so the last thing we need to do for a basic linux system would be to install our firewall. To do this open your terminal the same way we did earlier and type the following.
sudo apt-get update && sudo apt-get install ufw gufw
Confirm with Y and hit enter. This will install ufw and the graphical interface to ufw. To open the graphical interface, wait until the install is finished and then just type this into the terminal.
sudo gufw
Once the graphical interface opens click unlock so we can make changes, and then select "On" as the status. This will be default deny incoming and allow outgoing. We will configure this more in later tutorials but for now we are keeping it basic. Once done, click the x in the top right corner to exit and sigh in relief. You are finished!
Closing
I hope this helps guys. I was going to use pictures for every part of the install but i decided not to because it is only hurting you. You need to learn to read the screen and pay attention so I did this all textually. Soon to come will be more articles delving further into security, installing wallets and other fun stuff so stay tuned!

thanks. upvoted