Creating a bootable flashdrive

Windows: Disk Management, EASEUS Partition Master(paid)

Linux: parted, gparted, fdisk, cfdisk, sfdisk

You can also manage partitions from within the install media of both Windows and Arch Linux without having a working OS installed.

#https://github.com/SystemRage/py-kms/wiki/Office-GVLK-Keys
# Activate Office 2019 Pro Plus
cd 'C:\Program Files\Microsoft Office\Office16'
cscript ospp.vbs /inpkey:NMMKJ-6RK4F-KMJVX-8D9MJ-6MWKP
cscript ospp.vbs /sethst:192.168.1.40
cscript ospp.vbs /act
 
# https://docs.microsoft.com/en-us/windows-server/get-started/kmsclientkeys
# W10 Pro
slmgr /ipk W269N-WFGWX-YVC9B-4J6C9-T83GX
# W10 Edu 
slmgr /ipk NW6C2-QMPVW-D7KKK-3GKT6-VCFB2
# Set KMS server to a LAN one
slmgr /skms 192.168.1.40:1688
# Force activation now
slmgr /ato
# Disable Automatic Install of Suggested Apps 
reg add HKCU\Software\Microsoft\Windows\CurrentVersion\ContentDeliveryManager /v SilentInstalledAppsEnabled /t REG_DWORD /d 0 /f
# Disable App Suggestions in Start menu
reg add HKCU\Software\Microsoft\Windows\CurrentVersion\ContentDeliveryManager /v SystemPaneSuggestionsEnabled /t REG_DWORD /d 0 /f
# Disable popup "tips" about Windows
reg add HKCU\Software\Microsoft\Windows\CurrentVersion\ContentDeliveryManager /v SoftLandingEnabled /t REG_DWORD /d 0 /f
# Disable Windows Welcome Experience
reg add HKCU\Software\Microsoft\Windows\CurrentVersion\ContentDeliveryManager /v SubscribedContent-310093Enabled /t REG_DWORD /d 0 /f
# Disable xbox game DVR capture
reg add HKCU\Software\Microsoft\Windows\CurrentVersion\GameDVR /v AppCaptureEnabled /t REG_DWORD /d 0 /f
reg add HKCU\Software\Microsoft\Windows\CurrentVersion\GameDVR /v HistoricalCaptureEnabled /t REG_DWORD /d 0 /f
# Show file extensions
reg add HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced /v HideFileExt /t REG_DWORD /d 0 /f
# Opening explorer opens in THIS PC rather than RECENT FILES
reg add HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced /v LaunchTo /t REG_DWORD /d 1 /f
# Do not hide tray items when they get cluttered(? not sure)
reg add HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer /v EnableAutoTray /t REG_DWORD /d 0 /f
# Take Search off the taskbar
reg add HKCU\Software\Microsoft\Windows\CurrentVersion\Search /v SearchboxTaskbarMode /t REG_DWORD /d 0 /f
# Take Cortana off the taskbar
reg add HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced /v ShowCortanaButton /t REG_DWORD /d 0 /f
# Hide Task View button
reg add HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced /v ShowTaskViewButton /t REG_DWORD /d 0 /f
# Hide People button
reg add HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\People /v PeopleBand /t REG_DWORD /d 0 /f
# Show hidden files
reg add HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced /v Hidden /t REG_DWORD /d 1 /f
# Show hidden system files
#reg add HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced /v ShowSuperHidden /t REG_DWORD /d 1 /f
# Disable UAC prompts
reg add HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 0 /f
# Delete all taskbar shorcuts to get rid of Edge, Store and more
reg delete HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Taskband /v Favorites /f
# Kill and restart explorer.exe to apply most changes right now
taskkill /f /im explorer.exe
explorer.exe
Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Force
Set-ExecutionPolicy Bypass -Scope Process -Force; iex ((New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1'))
choco install -y mumble googlechrome notepadplusplus 7zip crystaldiskmark crystaldiskinfo keepassxc sharex openssh telegram windirstat jre8 everything teamviewer smplayer hwinfo qbittorrent
# Alternatively do a minimal install
choco install -y googlechrome notepadplusplus 7zip sharex openssh telegram windirstat everything smplayer 

You can download latest .ISO of Win 10, 8.1 and 7 directly from Microsoft's servers. Note that you'll have to spoof the user agent if you're on Windows, as you'll get redirected to the Media creator tool otherwise.

The W10 ISO contains both Home and Pro edition which you get to choose during installation. If you want to install a W8.1/7 version that is not available directly from MS, you could possibly (ab)use the …/sources/ei.cfg file to change installed version that is going to be installed.

You can download older versions of windows and different versions of W10 through this method

If you want something like Enterprise versions and such you'll have to resort to torrenting them and THEN CHECKING THE HASHES provided by Microsoft.

https://tb.rg-adguard.net

Boot from the flash drive. Remember to always select “Custom” where applicable. You can skip creating a Microsoft account by trying to login with a nonexistent email.

Windows usually gets all the drivers itself, but if something doesn't work as it should you might need to visit your motherboard or device manufacturer's website and download drivers/update firmware.

Windows usually downloads an outdated GPU driver so head over to AMD's or Nvidia's website depending on what GPU you have.

If you already have or had a W10 license, then your hardware ID combination(should be motherboard+CPU) is stored on Microsoft's servers and your license will be obtained automatically when you connect to the internet, provided you installed the same W10 version.

If you don't have a W10 license you can either:

1) Buy a license key from official source. Buying from unofficial sources/grey markets is exactly as illegal as cracking it. You'd be literally giving your money away to thieves. The keys are from hacked MSDN accounts, credit card frauds etc.

2) If you're in college or some sort of academic institute, they might have MSDN licenses, see if you can find a copy from their IT department.

3) Not activate W10 - you will not be able to use Personalization features and it'll nag you

4) Activate W10 with KMSpico. Defender will bitch about it, allow it manually in Defender after installing it. Alternatively you can use vlmcsd if you want an open source, more hardcore solution.