You now have a working Windows 10 computer in front of you. Make sure that it is indeed working. Right-click on the start menu and select "Device Manager." In my computer's case, it looked like this (left). Note the yellow triangle and exclamation point by the video controller. That means there's a problem. If you right-click on it and select "properties" you'll see this (right):

Windows could not find device drivers for the video adapter in my computer and is substituting its own generic drivers, which are inferior.

Remember when we were looking at whether this computer was 64-bit compatible and the information page mentioned display adapters? I hope I wrote the model number down because now I would Google to try and find video driver for my computer. This is a problem that you probably won't have, as you won't be upgrading a 15-year old computer. Chances are that Windows will find the various hardware drivers for your computer's components and install them, but always check the device manager 1st thing to be sure everything's working.

And what about activation?

Go to settings/update and security/activation and check. I saw this:

Microsoft digitally activated the computer when it recognized the hardware "signature". Even without a corresponding linked Microsoft account and even after swapping the drives. I love it when things work! And if you look at system information you'll see:

It is indeed a 64-bit operating system installed.

Now you can go crazy with it...install all the software that you normally use in your day-to-day work, either via the Microsoft Store or web sites (or Ninite or Patch-my-PC Home Updater). Perhaps in a future article I'll detail various Office Suite options, or go through how I customize a newly-created PC to make it my own. But that's another article. I hope this has been of some usefulness and am happy to answer any questions.