If you have forgotten the password of an old Outlook PST file, like me, then I would recommend SameTools PST Password Recovery Tool. I have used it myself and removed the password in just a few minutes without any data loss. This tool is very lightweight, user-friendly, and supports almost all versions of Outlook (2019, 2016, 2013, etc.). Just load the file and click on "Remove Password" - the job is done. If you want, you can try its free demo version first.