So it's the old document that you have lost.
Of course when writing something is as important as a book you should have been making (multiple) regular backups of you files on other, external, discs.
Just in case something like this should happen, or the drive should fail, or .....
(I guess you'll be doing that from now).
Was the drive that is was saved on a HDD or SSD? (There is little chance of recovering anything from a SSD except maybe the filename but no contents).
But first things first, there are a few things to try before resorting to Recovery software.
When you overwrote the file with the new one did Office create a backup of the old one? (it should have done unless you have deliberately turned backups off).
Look in file explorer, it will have the same name but will be a .bak rather than a .doc or .docx.
Of course if you have saved the new one more than once then the .bak will just be a version of the new one.
![image.png]()
If there is then rename it to something else and change the .bak extension back to .dox (or .doc) - Word will then be able to open it.
If there isn't a .bak, or it's the new file, then try right clicking on the .doc/.docx and selecting "Restore previous versions".
![image.png]()
You should get something like this, and if you are lucky it will be the file that you are looking for. Note the date on this previous version of cake recipes, it's from last February (UK style dating). It did open in my word processor with no problem:
If there are more then one then select and 'Open' them one at once to see if it is what you want, They will open in Word.
If it is the file you want then save it with a new name.
![image.png]()
Another possible option: Do you have OneDrive turned on?
If so then you might be able to get the previous version from there: <a href="https://support.microsoft.com/en-us/office/restore-a-previous-version-of-a-file-stored-in-onedrive-159cad6d-d76e-4981-88ef-de6e96c93893" ipsnoembed="true" rel="external nofollow">https://support.microsoft.com/en-us/office/restore-a-previous-version-of-a-file-stored-in-onedrive-159cad6d-d76e-4981-88ef-de6e96c93893</a>
PS. There is no need to post the same question more than once.