...I'm a Firefighter not a computer whiz
We already know that. That's why you're here.
You are now a computer firefighter.
Can you look at the external HD to see what you moved? If you moved instead of copied, you might have deleted your personal profiles, which is what the symptoms tend to indicate. It may not be too serious, if it worked for a week.
AS a last resort. the computer can be fixed, but you might not like what you have to do: Reinstall Windows.
You will lose everything on the computer, & it will be return to the state when you bought it.
What is the make & model of the computer?