Unfortunately, there is no way to undelete history.

Do you make regular backups of your computer data?

Thank You for your reply. I was unable to find a backup. (Spouse's computer) I thought it was being done on a schedule.... guess not!

When Windows 10 updates, it generally creates a snapshot of your files in a restore point. You can use a third party program to see when your last restore point was created and, if it was very, very recent, to copy out your old places.sqlite database file to potential substitution for your current one.

IMPORTANT: DO NOT USE SYSTEM RESTORE TO ROLL BACK EVERYTHING.

When using an older places.sqlite file, you would lose any new history and more recent bookmarks. However, you might be able to recover the bookmarks.

If you're inclined to look into it:

• Set Windows to show hidden files and folders: https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files

• Install the System Restore Explorer: http://nicbedford.co.uk/software/systemrestoreexplorer/ -- then run this program

• If you find a very, very recent restore point, look into this folder: C:\Users\username\AppData\Roaming\Mozilla\Firefox\Profiles

• In the Profiles folder, there may be one or more individual profile folders with semi-random names. Check inside for the last updated date of the places.sqlite database file.

If you want to try using that recent file, copy it out to a neutral location like Documents or Desktop. To avoid problems, don't restore it directly to its original location.

Ready for next steps?

Best is to first create an HTML or JSON backup of the bookmarks before trying to restore an older copy of places.sqlite.

• Bookmarks -> Show All Bookmarks -> Import & Backup

Thanks, I Appreciate the help, however I am more confused now than ever and a little afraid that I will mess up other files... Maybe he has them bookmarked somewhere.

Firefox doesn't create a backup of the history like is done for the bookmarks in the bookmarkbackups folder with compressed .jsonlz4 backups, so the only way to restore/recover deleted history is via an older copy of places.sqlite like posted above.

Thank You