How to Fix Outlook PST File Missing in Windows 10 (2 Ways)

You can learn why Outlook PST file missing in Windows 10 and 2 methods to easily fix it. You can also learn how to prevent similar problems occur again. Keep reading for more details.


By Clytze Updated on February 24, 2023

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Why is Outlook PST File Missing in Windows 10?

PST, short for Personal Storage Table, is an Outlook data file used to store your mail, events, and contacts. Recently, many users have reported that they have encountered the error of losing Outlook pst files in Windows 10 during use. To fix this problem, you must first determine what might be causing the problem. Outlook PST file loss can be caused by the following factors.

  • Corruption of PST file.
  • The mailbox has exceeded its size limit, causing problems with Office programs.
  • A conflict between Outlook software and other software that has recently been installed on the computer.
  • The PST file is temporarily located in the web server and thus becomes unavailable.

How to Fix Outlook PST File Missing in Windows 10

Now that you know what might be causing this problem, you can read on to learn how to solve it effectively. Next, this article will introduce two useful methods in turn. Each includes a detailed graphic tutorial.

Method 1. Check Your Outlook

The first method is to check your Outlook and recently installed computer software. It can help resolve problems caused by too many mailboxes or conflicts between different software on your computer. If your mailbox is full of necessary or unimportant data, it may cause PST file corruption and thus you cannot find it anymore. You can delete some Outlook files according to the steps below.

Option 1. Go to File > Mailbox Cleanup > View Mailbox Size.

Method 1

Option 2. Click your account under the Folder tab at the top of the Outlook screen. Go to Folder Properties > Folder Size.

In the pop-up window, you can see how much size is used and what's occupying your mailbox storage. After checking the mailbox storage, you can decide if it is necessary to delete some Outlook data files and even empty some folders, for example:

  • Junk folder.
  • Deleted items.
  • Unnecessary emails from your inbox.
  • Emails with unimportant files, attachments, or images.

Method 2. Create A New PST File

Apart from the first method, you can also solve the "lost Outlook pst file in Windows 10" issue by creating a new PST file. First you need to find the default PST file and then create a new Outlook data file. You can follow the steps below to get started.

Part 1. Locate the default PST file

Option 1: Go to the home page and right-click "Archives" on the left panel. Select "Open File Location" and you can locate the Outlook data file.

Part 1

Option 2: Go to Control Panel > Mail > Mail Setup-Outlook. Select Show Profiles > Properties > Data Files. In the Account Settings dialog box, you can find the .ost file and .pst file locations. Copy the location or directly click "Open File Location" to locate the Outlook data file.

Part 2. Create a new Outlook data file

Step 1. In the Account Settings dialog box, select "Add" under the tab "Data Files". In the next pop-up window, click "OK"

Step 2. Select the new file and click "Set as Default".

Step 3. Close the Mail Setup wizard.

Step 4. Restart Microsoft Outlook.

How to Prevent Outlook PST File Missing in Windows 10 Occur Again

After you have solved the problem of Outlook pst file missing in Windows 10, in order to prevent this problem from happening again and cause data loss, it is recommended that you create a backup of Outlook. In this way, even if there is a problem with your Outlook accidentally, you can use this backup for quick restoration. Safe and reliable Outlook backup software - AOMEI Backupper Professional can help you backup Outlook data easily.

  • It provides you with the Outlook backup function to backup any data you want to back up, except for emails, you can also backup attachments, calendars, contacts, etc. on Outlook.
  • It allows you to backup Outlook to multiple locations such as internal and external disks, USB drives, NAS devices, network locations, SD cards, cloud services, etc.
  • You can perform schedule backups according to your needs. You can set daily, weekly, m,onthly and event-triggered scheduled backup tasks.
  • This software also supports multiple Windows PC operating systems, including Windows 11, 10, 8, 7, XP, and Vista.

You can download and install this professional backup software, and then start backing up Outlook according to the graphic tutorial below. If you are a Windows Server user, you can choose the AOMEI Backupper Server version.

Download Free Trial Win 11/10/8.1/8/7/XP
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Step 1. Open Outlook, type email and click Connect, then follow the on-screen instructions to add the Outlook account.

Add Account Oulook

Step 2. Open AOMEI Backupper Professional. In the main interface, click Backup > Outlook Backup.

Outlook Backup

Step 3. Click Add Outlook data and select the Outlook folder you want to backup. Then click OK.

Add Outlook Data

Step 4. Then click the box below to select the backup destination. It can be a local path, network or NAS location, or cloud drive to store your Outlook emails.

Select Backup Destination Path

Schedule Backup: You can set different  backup frequencies, like“Daily”, “Weekly” or “Monthly” . Make sure the option “Wake the computer to run scheduled task” is selected.

Schedule Backup

Backup Scheme You can Enable Automatic Backup Cleanup to delete old backups regularly. This feature can solve the storage full issues.

Step 5. Click Start Backup to backup Outlook automatically.


This post explains why Outlook PST file missing issue in Windows 10 occurs and two ways to fix it. In order to prevent data loss caused by similar problems in the future, it is recommended to use a professional backup software - AOMEI Backupper Professional to back up Outlook. In this way, data security can be protected from leakage to the greatest extent.

You can set the regular backup frequency to automatically back up Outlook according to your own needs, and you can also back up Outlook to the hard disk or a variety of different devices. You can download this software to explore more.

Clytze · Editor
Clytze, an editor at AOMEI Technology, is passionate about safeguarding your digital world. She dedicates her expertise to empower users like you in data security and recovery. She firmly believes that everyone should have the tools and knowledge to protect their digital assets through computer backup, seamless disk cloning, and efficient file synchronization. Clytze is your trusted guide on the journey to data safety.