Let me try this again....
The problem with password questions is that we don't know if you're the owner of the device or account. So instead of helping you hack the machine, possibly giving someone a means to gain access to files they ought not to have access to, let's instead look at the Yahoo account.
Try going to Yahoo and resetting the password (https://help.yahoo.com/kb/SLN2047.html)
It gives three options...
- Alternate email address
- Mobile phone
- Security questions
Assuming you have access to (and set up) the email address or mobile phone to which the account was set up, those are the easiest.
The security questions, you'd have to remember the answers AND the case that you put them in. ("Mighty" is not the same as "mighty")
Once you regain access to the Yahoo account, reset the Microsoft
Once you reset the Microsoft, you can again access the laptop.
It's a roundabout way, but it's better (and more secure, and safer, ...) than hacking the machine, or resetting it (and losing anything you might have on it.)
Good luck!!!