A few days ago, one of my old Outlook PST files was not opening because I had forgotten its password. When I could not remember the password even after several attempts, I used the Softaken PST Password Recovery Tool, and to be honest, this tool turned out to be better than my expected.
What I liked:
Removed any type of password (long, complex) in minutes
Not a single part of the data was deleted or corrupted
Very easy interface, no technical knowledge required
Outlook is not required; the tool does everything on its own
If you also want to open your password-protected PST file and recover Outlook data, then I would definitely recommend this tool of PST Password Recovery.