Ok, so if you were like me you were probably searching the internet for ways to save deleted world that you didn't mean to delete. The problem is everywhere you look it is confusing (because people don't know how to contruct a well thought out sentence), its not what you are looking for, or ther isn't actually an answer. So here I will do my best to offer a solution to your problem.

1. Open two separate File Explorer windows.
   
2. *Look at the note below.*
   
3. Enter "C:\Users\Username\.minecraft\saves" into one of the File Explorer search bars (without quotations and put your Minecraft username in place of "Username" or your username for the computer).
   
4. Enter "C:\Users\Username\AppData\Roaming\.minecraft\saves" into the other window's search bar (without quotations and put your Minecraft username in place of "Username" or your username for the computer).
   
5. Now copy/past or cut/move the world(s) you would like to recover into the appropriate location.
   
6. Double check that it worked by starting up Minecraft and viewing your single player worlds.
   

*Note: Step 3 brings up your deleted worlds and step 4 brings up you worlds you have not deleted.*

If this did not help or you need further assistance please contact me.

With this information you should also be able to move worlds between computers and duplicate them.