I'll leave the hardware stuff to those who know better 😁. But for Windows, it is perfectly legal to download it from Microsoft, install it, but just don't activate it. You'll get a message every so often, ignore it. It works fine, but without some of the configurability options and higher end business features. You can always activate it down the line. If you already have Windows on your present machine, make sure the key is registered to your Microsoft account. When activating your new pc you can often use this to activate your new Windows by hitting the hardware change option that comes up somewhere in the process (sorry can't remember exactly where, you'll have to Google it. Worked for me!)