Where is the hard drive?

[RandomGrinch]

Is the lack of password the main problem, or do you want data recovery from corrupted media?
The two problems need slightly different approaches.

If it is a password issue, then here are some good methods to work through:

https://www.makeuseof.com/tag/3-ways-to-reset-the-forgotten-windows-administrator-password/

Although involved (but satisfying! ), I have used method two, many times to gain admin rights over a locked out PC.

If it's purely data recovery, then a Linux live USB stick is the way to go.

 

[JohnD]

Lack of password is the problem. User is deceased.

 

[RandomGrinch]

Lack of password is the problem. User is deceased.

Then, as above - I would go through the steps of creating a new admin account.
The steps in the link are pretty well laid out, but let us know if this isn't for you.