I can answer this.
If you took advantage of the free upgrade to win 10 during the availability.
Then you can., if it is the same pc.
If not it will be hit or miss,
You need to install the microsoft media creator tool then download win 10 built in to the app.
Then select the similar version you had before.
When prompted for a license. elect I don't have one.
That is because your first time it was saved as a digital copy.
I will look for a guide.
Here is one:
https://www.youtube.com/watch?v=9iUX7sQeOkg
another is
https://www.youtube.com/watch?v=QdNL-pvvXH4

It takes a lot longer than the video.

There is no such thing as stupid questions , Just stupid answers.