Outlook PST files become password protected

Question

Outllok PST file became password protected without any instruction. I have no idea what the password is,

When you now switch on Outlook it is now asking for a password before trying to start the program.

Any ideas?

Answer 1

@Martin Morris said

Outllok PST file became password protected without any instruction. I have no idea what the password is,

Did you move/copy the PST to a new PC? If so, this is a know problem. But no simple solution. You will have to use a third party tool to access the PST.

[External Non-Microsoft Site] https://www.slipstick.com/problems/pst-repair/remove-a-password-from-a-pst-file/

When moving a pst file to a new computer, Outlook will often ask for a password. You may not be forgetful - the moving process does something to make Outlook think there is a password. You will need to use a password recovery utility to get the password. (It will likely be a random generated password, not a passphrase or password you would have used.)

Answer 2

Hi @Martin Morris

I understand how concerning it is when Outlook suddenly requests a password that you do not remember setting.

Since Outlook cannot fully start, please close it and open Control Panel > Mail (Microsoft Outlook) > Data Files. Check which data file is listed and whether it is an additional archive or the default file used by your email account.

If the password-protected PST is only an additional archive, select it and choose Remove. This only disconnects the file from the Outlook profile and does not delete the PST from the computer. Outlook may then start without requesting that file’s password.

However, please do not remove it if it is marked as the default delivery location, especially for a POP account. In that case, could you share a screenshot of the password window with any personal information hidden, and confirm:

• Does selecting Cancel allow Outlook to continue?
• Is the affected account POP, IMAP, Outlook.com, or Microsoft 365?
• Was an old PST, archive, or backup recently added or restored?

These details will help determine whether the prompt comes from an optional archive or the main mailbox data file.

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