Hi
@Livid, and welcome back. I hope that you're feeling well now, or at least better! In your absence, both Linux Mint and VirtualBox have updated, and I would recommend that you get the new versions of both (plus the new checksum file)... I will provide links to them to make it easier. I just returned from Windows where I wrote and followed these instructions that I made for you. They are quite extensive and detailed so hopefully you will not have any mistakes if you follow along carefully. There are about 3 dozen steps... so take your time. You will be installing a new Windows program and a full Linux operating system... this will quite likely take up to an hour at least, and maybe even longer (not counting the download times).
1. Download new version of VirtualBox. Right-click on this link and choose "Save As" to download to your hard drive:
http://download.virtualbox.org/virtualbox/5.2.4/VirtualBox-5.2.4-119785-Win.exe
2. Download new version of Linux Mint. Right-click on this link and choose "Save As" to download to your hard drive:
http://mirrors.kernel.org/linuxmint/stable/18.3/linuxmint-18.3-mate-64bit.iso
3. Download new version of Linux Mint checksum file. Right-click on this link and choose "Save As" to download to your hard drive:
https://ftp.heanet.ie/mirrors/linuxmint.com/stable/18.3/sha256sum.txt
4. Verify the checksum of the new Linux file like you've done before. When finished, close that program.
5. Install VirtualBox (during install, it will prompt to install 3 more helper support apps: USB, Network adaptors, and Network service... install these too)
6. Start VirtualBox, then click the big blue "New" button
7. Give the new virtual machine a name (Linux Mint 18.3 MATE says exactly what it will be, and you can install others later)
8. Change the type from Windows to Linux (it may have done this automatically)
9. Change the version to Ubuntu (64-bit) (again, it may have done this automatically... Mint is Ubuntu-based, so this setting is okay)
10. Click Next
11. Accept the default memory size, click Next
12. Leave the next setting ticked for "Create a virtual hard disk now" and click Create
13. Leave the next setting ticked for VDI (Virtual Disk Image) and click Next
14.
Change the next setting to Fixed size, and click Next
15. On the next screen, File Location and size,
change the 10.00 GB to 15.00 GB. Linux Mint needs more than 10, so this is important. Click Create (and wait for it to complete the virtual drive creation... takes a couple of minutes)
16. This completes this part of the setup and shows your new Virtual Machine (highlighted in blue) in a "Powered Off" state.
17. Click the Settings button now.
18. In the selections on the left, click on Storage.
19. Then, in the middle, under Storage Devices, it shows a small circle with a + sign and a small square with a + sign. Click on the circle with + sign, and then click on Choose Disk.
20. This opened up in my Downloads folder.... but the important part here is to find your linuxmint-18.3-mate-64bit.iso file... then double-click on that file.
21. Back in Storage Devices, it now shows your .iso file under "Controller: IDE"... so click OK at the bottom of this screen.
22. NOW... back at the main screen... click the green Start button.
23. You can let the 10 second timer expire, or you can hit Enter... then hit Enter again for "Start Linux Mint"
24. You can click the little blue boxes marked with X in the banners in the top of the window to close those notifications (give them a quick read too).
25. You are now at at Linux Mint desktop.... double-click on the Install Linux Mint icon.
26. From here on, this is also how you would install to your computer hard drive, instead of a virtual drive... so try to pay close attention if you think you will want to do a full installation later.
27. The first screen wants your language... choose and then click Continue
28. The next screen prompts to install third-party software. You can check this unless it then prompts to disable Secure Boot. If if wants to disable Secure Boot, then do not check this option. Click Continue.
29. The next screen defaults to "Erase disk and install Linux Mint". Yes, you want this! It is only referring to the virtual disk, not your whole hard drive. Click Install Now.
30. A final warning appears about writing changes to disk... click Continue.
31. The next screen is to choose your Time Zone. So pick the appropriate Time Zone and then Continue.
32. The next screen is to choose your keyboard layout. Pick the appropriate keyboard and then Continue.
33. The next step requires you to fill in several items:
a. Your name (First name, or First and Last, whatever is fine)
b. Your computer's name (this is mostly for home networking, a short name is best, like HP, or Dell, or something like that)
c. Pick a username (must be lowercase, it will probably default to the name you picked above, but you can change it)
d. Choose a password and Confirm your password (you have to enter it twice, and its case-sensitive....
DO NOT FORGET THIS PASSWORD!)
e. I recommend to "Log in automatically" and DO NOT Encrypt Home Folder. (This is an experiment and lesson in Linux and VirtualBox... not computer security. At some point later you will probably delete this virtual machine.)
f. Click Continue
34. It will now install Linux Mint into the virtual hard disk... takes about 10-15 minutes
35. When finished, choose Restart Now
36. It will prompt to remove the installation media... just hit Enter
On my computer, after it restarts... it comes up in full-screen. You can untick the box to "Show at startup" and then close the "Welcome Screen" that first appears. One of the very first things you should do is open a Terminal (the little black square box in the lower left of the panel (Linux name for taskbar). You may or may not have much need for the command line, but it is extremely helpful and folks on the forum will use it to give you assistance, if needed. You will notice the "command prompt" shows your
username@computer-name ~ $ -- from there, type
sudo ufw enable and hit Enter. It will prompt you for a password, but you will not see anything type, not even ****, so type carefully and hit Enter. It will then report that your Firewall is active and enabled. After that, if you are connected by ethernet you should already be on the internet... if not, you will need to look at the icons on the right side of the panel... one of them will show wireless connections and allow you to access your home WiFi.
Whew! I hope you're up and running! I installed Mint 18.3 MATE myself to create these instructions, so they should be fairly accurate. Installing other Linux distros will follow along about the same way, but you have to be able to adjust on the fly if something is a little different. Some distros may not run full screen, but you can still get an idea of how they work if/when you install any others.
To shut down Linux Mint, just choose the Menu button in the far left corner of the panel, and choose Quit. After that, you can then exit VirtualBox. If you want some help with Linux Mint, they have a User Manual that may help here:
https://linuxmint.com/documentation/user-guide/MATE/english_17.3.pdf
Cheers