how do i fix an error message which says my computer cannot find my outlook email files

John Broome 0 Reputation points
2026-11-03T23:25:31.0666667+00:00

My outlook emails for my optusnet account disappaeared of both my desktop and laptop. The error message says the computer cannot find the outlook email files. The problem occurred on both the ;aptop and the desktop at the same time. I have checked online and downloaded the outlook files from the cloud but i cannot get these to open. just looking to talk to someone to try to fix this.

Outlook | Windows | Classic Outlook for Windows | For home
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  1. Emma1-N 14,895 Reputation points Microsoft External Staff Moderator
    2026-11-04T06:36:26.8+00:00

    Welcome John Broome,

    Thanks for reaching out to Microsoft Q&A Forum. I understand that your OptusNet emails disappeared from classic Outlook on both your desktop and laptop at the same time. Outlook now says it cannot find your email files, and the files you downloaded from the cloud will not open.

    To help narrow this down, could you please share:

    • The full error message, including the file path it shows. Does the path include OneDrive, and does the file name end in .pst or .ost?
    • Is your OptusNet account set up in Outlook as POP or IMAP? You can check this under File > Account Settings > Account Settings, in the Type column of the Email tab.

    Please make sure you already tried the Q&A Assist steps. In addition, please try the following:

    1, Find out which file Outlook is looking for

    • Open Outlook, or open Control Panel > Mail > Data Files if Outlook will not start.
    • Write down the full location of the data file for your OptusNet account.

    2, Make sure the file is stored on your computer, not only in OneDrive

    • Open File Explorer and go to Documents > Outlook Files, and also OneDrive > Documents > Outlook Files.
    • If the file has a cloud icon, right-click it and select Always keep on this device. Then wait for the green check mark before opening Outlook.

    3, Search the whole computer for the data files

    • In File Explorer, select This PC and search for *.pst, then do the same for *.ost.
    • Look at the file size and the Date modified column to find the most recent file with your email in it.

    4, Move the file out of the OneDrive-synced folder and point Outlook to it

    • Close Outlook and copy the .pst file to a local folder, such as C:\OutlookData.
    • In Control Panel > Mail > Email Accounts, select your OptusNet account and select Change Folder (for a POP account). Then select New Outlook Data File and browse to the copied file.
    • Outlook data files can be damaged when OneDrive syncs them, so keeping them in a local folder can help prevent this from happening again.

    Looking forward to your update.

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  2. AI answer

    2026-11-03T23:26:43.5+00:00

    Because the OptusNet messages disappeared from both computers simultaneously, first check the mailbox through Optus webmail and contact Optus if the messages or mailbox are missing there; repairing Outlook cannot restore server-side data.

    1. Check whether the OptusNet mailbox still exists

    1. Sign in through OptusNet webmail rather than Outlook. Optus confirms that existing OptusNet accounts can be accessed online. ^1^
    2. Search for several missing messages and inspect all folders.
    3. If you cannot sign in, use Optus password recovery. ^2^
    4. If the mailbox or messages are absent online, contact Optus Support and ask them to check:
      • Whether the mailbox remains active.
      • Whether it was affected by the OptusNet account review or platform migration.
      • Whether server-side email can be recovered.

    Optus has been reviewing inactive OptusNet mailboxes and migrating the service, so an account-level check is appropriate when two computers lose access together. ^3^ ^4^ Contact Optus through its support page. ^5^

    2. Open the downloaded Outlook file correctly

    Since downloading the files did not make them open automatically, check the filename extension in File Explorer. The useful recovery path below applies if the file ends in .pst.

    Make a copy of the downloaded file first and work with the copy. Then, in classic Outlook:

    1. Select File → Open & Export → Open Outlook Data File.
    2. Select the copied .pst file and choose Open.
    3. Look at the bottom of Outlook’s left folder pane for an additional folder tree, then expand it to find the old messages. ^6^

    Do not use File → Open or double-click the file in File Explorer.

    If using new Outlook, go to Settings → Files → Outlook Data Files → Add file. Opening PST files there requires classic Outlook to be installed, and both Outlook versions must be either 32-bit or 64-bit. ^7^

    A file ending in .ost is an offline cache, not a normal portable backup. It cannot be handled as a PST using the steps above.

    3. If Outlook finds the PST but cannot open it

    Repair a copy of the PST with Microsoft’s Inbox Repair Tool:

    1. Close Outlook.
    2. Locate and run SCANPST.EXE. For Outlook 2016 or 2019, Microsoft lists: C:\Program Files (x86)\Microsoft Office\root\Office16
    3. Select Browse, choose the copied .pst, and select Start.
    4. If errors are found, select Repair.
    5. Reopen Outlook and open the repaired PST through File → Open & Export → Open Outlook Data File.
    6. Check Recovered Personal Folders and Lost and Found for recovered messages.

    Microsoft recommends backing up the data file before repair; some items cannot be recovered if they were permanently deleted or damaged beyond repair. ^8^

    4. If webmail contains the messages but Outlook does not

    This indicates an Outlook connection or profile problem rather than lost server mail. Create a test profile without deleting the old one:

    1. Close Outlook.
    2. Open Control Panel → User Accounts → Mail → Show Profiles.
    3. Select Add, name the profile, and add the OptusNet account using the current settings supplied by Optus.
    4. Select Prompt for a profile to be used.
    5. Start Outlook and choose the new profile.

    Do not remove the original profile until its local data files have been backed up. ^9^

    Talking to support

    For the missing mailbox or messages on Optus webmail, contact Optus first because Microsoft cannot inspect an OptusNet server mailbox. For help opening or repairing a local PST in Outlook, Microsoft’s support page can connect eligible home users to technical support, potentially by chat. ^10^

    Have the exact error text, Outlook version, file extension (.pst or .ost), file size, and the Optus webmail result ready for the support agent.

    References

    1. Accessing your OptusNet email online
    2. Forgot password - Optus
    3. We're checking the status of your OptusNet email service
    4. We're making improvements to our OptusNet service
    5. Help & Support - Optus
    6. [Classic Outlook](https://support.microsoft.com/outlook/open-and-close-outlook-data-files-pst)
    7. [Classic Outlook](https://support.microsoft.com/outlook/open-and-find-items-in-an-outlook-data-file-pst#open-an-outlook-data-file-in-classic-outlook)
    8. Repair Outlook Data Files (.pst and .ost) | Microsoft Support
    9. Classic Outlook not responding, stuck at "Processing," stopped working, or freezes | Microsoft Support
    10. Contact Microsoft customer support | Microsoft Support
    AI-generated content may be incorrect. Read our transparency notes for more information.

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