How to download and install Windows 10 legally

1. Download and create Windows 10 installation media from https://www.microsoft.com/en-us/software-download/windows10;
2. Click the blue “Download tool now” button and save the MediaCreationTool file on your Desktop;
3. Open the MediaCreationTool;
4. After “Getting a few things ready” read the “Applicable notices and license terms” and click Accept;
5. “What do you want to do?”, choose: “Create installation media (USB flash drive, DVD, or ISO file) for another PC”;
6. “Select language, architecture, and edition”. Language: English (United States), Edition: Windows 10, Architecture: 64-bit (x64) and click Next to continue;
7. “Choose which media to use”
   1. USB flash drive (It needs to be at least 8 GB);
   2. ISO file (You’ll need to burn the ISO file to a DVD later) or you can create a bootable USB drives with Rufus.
8. If you choose the ISO file then next select a path to save the Windows.iso file;
9. Click Finish after you see “Burn the ISO file to a DVD” because you will create a bootable USB drive;
10. Now you can boot your PC/laptop to the bootable USB and install Windows 10;
11. On Windows Setup you can select:
    1. Language to install: English (United States);
    2. Time and currency format: English (United States);
    3. Keyboard or input method: US
12. After you enter your language and preferences click “Next” to continue and then “Install now“;
13. Enter a valid Windows product key because is the first time you’re installing Windows on your PC/laptop;
14. Select the operating system you want to install:
    1. Windows 10 Home
    2. Windows 10 Home N
    3. Windows 10 Single Language
    4. Windows 10 Education
    5. Windows 10 Education N
    6. Windows 10 Pro
    7. Windows 10 Pro N
15. Accept the license terms and click “Next”;
16. Which type of installation do you want?
    1. Upgrade: Install Windows and keep files, settings, and applications. The files, settings, and applications are moved to Windows with this option. This option is only available when a supported version of Windows is already running on the computer;
    2. Custom: Install Windows only (advanced). The files, settings, and applications aren’t moved to Windows with this option. If you want to make changes to partitions and drives, start the computer using the installation disc. We recommend backing up your files before you continue.
17. Where do you want to install Windows? after you select Custom: Install Windows only (advanced):
    1. If you don’t already have 2 partitions created with partition software then click New to create a partition to install Windows;
    2. The Windows 10 system requires Hard disk space: 16 GB for 32-bit OS or 20 GB for 64-bit OS but you can choose more space because you will install other software too on that partition. I only recommend the second partition for the BACKUP files if you don’t have an external HDD/SSD;
18. Wait till Installing Windows: Copying Windows files, Getting files ready for installation, Installing features, Installing updates, Finishing up;
19. Setup the Basics like region, keyboard layout, add a second keyboard layout, then network, account (set up for personal use or set up for an organization). You can Sign in with Microsoft or use an Offline account. If the Offline account was selected then choose Limited experience to continue and create an offline account when Who’s going to use this PC? message appears;
20. Choose privacy settings for your device:
    1. Online speech recognition;
    2. Find my device;
    3. Inking & typing;
    4. Location;
    5. Diagnostic data;
    6. Tailored experiences.
21. Do more across devices with activity history: Yes or No;
22. Let Cortana help you get things done: Not now or Accept.
23. Don’t turn off your PC till Windows will start.

If you don’t have a Windows 10 product key but you want to test it at home then you can go to Microsoft Evaluation Center to Download Windows 10 Enterprise and use it for 90 days. You can reinstall it after 90 days or you can reset the activation timer to 90 days for the Windows 10 Enterprise through Command Prompt App by running the following command line as Administrator:

slmgr.vbs –rearm

So, even if there are 10 days left for this trial period, the command will reset the activation timer to 90 days and not to 100 (10 + 90).

After restarting the operating system the evaluation will continue. To verify how many days you will continue the evaluation run as Administrator in Command Prompt the following command line:

slmgr.vbs -dli

How to Open the Command Prompt or Windows PowerShell as Administrator in Windows 10?

Press Windows+R to open the “Run” box. Type “cmd” into the box and then press Ctrl+Shift+Enter to run the command as an administrator. Press Windows+X or just right-clicking the Start button and click to Windows PowerShell (Admin).