Windows 7 End of Life
As of now free windows 10 upgrade period is ended, your only option is to purchase Win 10 Licence.
If you not sure which one to go with, please consider asking your self these questions.
1: Do you need advance user management capability? 2: Are you adding your computer into domain? 3: Do you have extra money?
If your answer for any of this questions was YES, buy WINDOWS 10 PRO. Otherwise windows 10 home editing will do just fine.