To reset an Outlook PST password, you can either use native settings within Microsoft Outlook (if you know the current password) or a professional password recovery utility (if you have completely forgotten it).
Method 1: Change or Remove Password via Microsoft Outlook

If you already know the current password and simply want to modify or completely clear it, you can handle this directly in Outlook:
2. Select Data File: Switch to the Data Files tab, choose your password-protected .pst file, and click Settings.
3. Modify Credentials: Click Change Password, provide your current password, and type your new one.
• Note: To entirely remove the password restriction, leave the new password fields completely blank.

Method 2: Reset a Forgotten Password

Microsoft does not provide a built-in "Forgot Password" utility for offline PST files. If you are entirely locked out of your data file, you will need a third-party application to remove or bypass the encryption.
Recommended Utility: For a secure and automated approach, you can use the Recoveryfix PST Password Recovery Tool. This specialized program bypasses complex encryption algorithms without risking data loss or altering your existing mailbox folders. It allows you to quickly load the secured PST file, run the recovery process, and either erase the lock entirely or assign a fresh password to gain instant access to your emails.