Summary: This guide summarizes the causes behind the ‘Outlook PST cannot be opened’ issue. In this guide, you will learn various methods to fix this error in MS Outlook for Windows. Also, you’ll get to know the ways to extract data from the problematic PST file and save it in a new working PST file for quick import.
Microsoft Outlook stores the mailbox data either in OST or PST file format. The Personal Storage Table (PST) file is created by default when you add or configure a POP account in MS Outlook.
Outlook syncs the mailbox data, such as emails, attachments, contacts, calendar, notes, etc. from the email server and saves it in the PST file. The PST file format is also used to backup and archive the Outlook Exchange, Office 365, and IMAP emails. One can open and access the emails stored in a backup PST file anytime via Outlook options. However, sometimes PST becomes inaccessible and thus, an error such as Outlook PST is in use and cannot be Opened, appears.
The file C:\Users\username\AppData\Local\Microsoft\user name\username.pst is in use and cannot be accessed. Close any application that is using this file, and then try again. You might need to restart your computer.
Reason for ‘Outlook PST cannot be opened’ Error
While it may appear that the PST file is being used by some other application, quitting all applications or restarting the computer might also not resolve this error. There could be several reasons that can trigger this error, such as,
- Improper Outlook termination causing outlook.exe to run in the background
- PST file backup running in the background
- Outlook conflicting software or faulty Add-ins
- Damaged or corrupt PST file due to oversize, disk errors, system or Outlook crash (most common reason)
- Sometimes anti-virus and anti-spyware programs delete files without headers, causing the PST to become inaccessible
Signs of PST File Corruption
Application crashes, frequent freezes, or failure to launch Outlook are some of the effects of PST file corruption. Since there are a number of reasons due to which PST files can get damaged/corrupt, users seldom have control over it. The most common reason is an oversized or large PST file, which is prone to corruption due to integrity issues. Thus, staying aware of the causes behind PST file corruption and the solutions is the best way to stay afloat in troubles.
In a nutshell, the corruption in PST file results in the error that prevents you from accessing your emails on MS Outlook. Thus, you must fix the error quickly to get back access to your emails.
Methods to Fix ‘Outlook PST cannot be opened’ Error
Follow these methods in the given order to resolve this Outlook PST file error,
Method 1: Close All Processes and Programs
As the error suggests, you must find and close all the programs that might have access to the PST file and thus, preventing MS Outlook from accessing the same. To find out if any Outlook related processes are running in the background and to end them, follow these steps,
- Right-click on the Taskbar area and choose Task Manager
- Click on ‘More Details’ and then go to the Processes tab
- Now find the processes by the name ‘outlook’, ‘communicator’, ‘Lync’, ‘UCMAPI’ and end them all. To end them, simply click on the process and then click the ‘End task’ button
- Exit Task Manager and restart Outlook
Method 2: Open MS Outlook in Safe Mode
By opening Outlook in safe mode, you can find if the problem is caused by some faulty add-ins. If Outlook opens in safe mode without any hiccup, you must uninstall the third-party add-ins from the Outlook while running in safe mode. The steps are as follows,
- To open Outlook in safe mode, close MS Outlook and then press Windows + R
- Type outlook.exe / safe and press ‘Enter’
- If the error disappears, go to File>Options>Add-ins and disable all add-ins
- Then launch Outlook. Start enabling add-ins one-by-one to spot the faulty one
Method 3: Fix PST File Errors with Inbox Repair Tool
If the above methods fail to resolve the Outlook PST error, there could be a problem with the PST file itself. As discussed earlier, a PST file may get damaged or corrupt due to various reasons.
However, MS Outlook comes with SCANPST.EXE, an Inbox Repair Tool which is located in the MS Office installation directory. The utility helps to repair a damaged or corrupt PST file which can’t be accessed in Outlook. By repairing the PST file, you may resolve the Outlook PST file error.
The steps are as follows,
- Quit MS Outlook and go to the Installation directory of MS Office. It is usually,
C:\Program Files\Microsoft Office\ OfficeXX or C:\Program Files (x86)\Microsoft Office\OfficeXX
The XX, in the end, represents the Office version (see screenshot below).
- Find and launch SCANPST.EXE utility
- Click ‘Browse’ and choose the PST file
- Click ‘Start’. This will scan the PST file and check for errors
- If errors are found, the utility will display the ‘Repair’ button, click on it and wait for the repair to finish
- During repair, you may find the Inbox Repair Tool ‘Not responding’. However, do not close it as this is how the utility works
- If the utility does not exit the ‘Not responding’ status or crashes and stops working while repairing the PST file, you can use a more advanced PST repair software discussed in the next method.
The reasons for Inbox Repair Tool failure could be many as the utility does not support an encrypted or PST file larger than 2 GB.
Method 4: Fix the Error by using Advanced PST Repair Tool
If none of the above methods, including the Inbox Repair Tool, resolve the error, you can download, install, and run a much more advanced and powerful PST Repair Software, i.e. Stellar Repair for Outlook.
This software works deftly to fix the error ‘pst cannot be accessed’. Once it repairs the PST file, the tool also assists you in extracting all mailbox contents and saving them in a new usable PST file that can be directly imported into Outlook. The steps to fix Outlook PST file are as follows,
To Repair Outlook Data Files Manual Guide
- Download, install and launch Stellar Repair for Outlook
- On the home screen of the software, you’ll find two options in Select PST File for Repair dialog box
- ‘Browse‘ – use this option if you know the location of the PST file
- ‘Find ‘ – use this option if you don’t know the exact location of PST file on your computer
- Once PST file has been selected, click on ‘Repair’ to initiate the scanning process
- All PST contents will be displayed in a tree-view list within the left-hand panel of the software window. You can browse and check any item by selecting it
- Select the files/folders which you want to recover and click ‘Saved Repaired File’ button from the Home menu
- Choose output format as PST from the multiple saving options and browse to the location where you want to save the recovered PST file
- Click ‘OK’ to start saving the data to a new PST file
Once the process completes, a pop-up will inform you of the same.
By following this guide, you can fix the common PST file errors, such as Outlook PST cannot be opened. However, if the error is not fixed by applying the manual methods, you can attempt to repair the PST file by using the Inbox Repair Tool or a more advanced Outlook recovery software such as Stellar Converter for Outlook. With this tool at hand, you won’t need any other product to fix any minor or major PST file issues in MS Outlook on Windows.