restore from backup

Went in to make an entry and was unable to tag.  Ver 1.4x. Tag window would not open. Tag search window worked fine. Today button inoperative.
Upgraded to ver 2.39 and lost my journal. Unable to restore from backup so no previous tags, or entries.
How do I restore from backup?
All my data is grayed out when I try to open them but I can open the text files and see the tags and entries in notepad.