Repair OST File Manually

Updated on April 04, 2026 by Deepika Singh

Before discussing how to repair corrupted OST file, let’s understand what is OST file? Microsoft Outlook creates an OST file, an offline data file. It's used to keep a backup of Exchange Server mailbox data. OST files are local files that allow users to view their emails and other mailbox information when they don't access the Internet. For some causes, a user's Exchange server mailbox can become corrupted or even removed from the server. Don’t worry — deleted files are often still saved on your computer (in MS Outlook) and can be recovered using free OST Recovery Methods.

Most common causes of missing or corrupt Outlook OST files:

• A sudden power outage may result in the loss of the OST file.
• If the storage drive where you saved the OST file is infected with these malicious programs, the OST file may get corrupted.
• This could be the result of a network outage or a loss of internet access.
• If this occurs during OST file synchronization with the Exchange server, the OST files will become unreachable.
• Internal Outlook codes are one of the most typical causes of OST file corruption.
• If the MS Outlook application is unintentionally closed without saving any data, the Outlook data will be corrupted.
• In some situations, some of the installed plug-ins that impairs the general performance of the Outlook application can cause the OST file to be corrupted.

To avoid these situations, you need to repair OST files. Hence, here we are trying to solve these issues using manual methods. You can also use professional tools for this task. However, I recommend you to try the manual method first to recover/repair OST file. So let's start with manual tricks immediately.

 

05 Free Manual Methods for OST File Recovery

Method 1. Repair Outlook OST File Using Upload Folder

Users can use this manual method to repair OST files that are badly damaged or corrupted. It's a simple and easy-to-use method that any user can easily deal with.

All you need to do is follow the steps given below:

1. First, right-click on the OST file folder and select the Properties option.
2. In the dialog box, click the Clear Offline Items option.
3. Next, hit on the "OK" button.
4. Now, select "Send/Receive" option in the Outlook ribbon.
5. Now you are require to click on "Update folder" to save the changes made.

Now, you can check out whether this process repaired and recovered OST files or not. If not, move on to the next method

Method 2. Repair OST File With In-Built Tool Scanpst.exe

Before Outlook 2010, users had Scanost.exe as the only option to repair OST files. However, after the changes in Outlook 2010, similar issues can be fixed by ScanPST (Scanpst.exe). If you want to repair OST and PST files both, you can use the Scanpst.exe tool built into it. It is a free tool from Microsoft that checks all errors and will help you repair damaged OST files. Working with Scanpst.exe (Inbox Repair Tool) requires a few steps. The steps are listed below:

Before starting any OST file repair, you need to find the OST file first. After that, users can use the scanpst.exe utility. Follow the steps below to use scanpst.exe.

1. You need to press Win+R key to open the "Run".
2. Here you need to type the "C:\Program Files (x86)\Microsoft Office\root\Office16" and then click "Ok" tab to proceed further. Note: – The above path only applies to Outlook versions later than Outlook 2013. But in case you are using Outlook 2013 use "C:\Program Files (x86)\Microsoft Office\Office15" instead.
   
3. Now open the scanpst.exe. tool on your system.
   
4. Now you can click the Browse button, to find the OST file that you want to repair, and click Start.
   
5. When the scanning is finished, click the "Repair" button to repair OST file.Note: Before clicking the 'repair' button make sure that you are backing up the scanned file by checking "Make a backup of scanned file before repairing".
   
6. When the repair process is complete, the message "Repair Complete" will appear on the screen and you are now finished repairing your OST file.
   

Method 3. Repair Corrupt OST File by Recreating a New OST File

In this method, we are trying to recreate corrupt OST file in order to fix certain OST file errors, which are mainly occurred due to corruption or damages and thereby access all of your Outlook data. This process applies to Outlook 2021, 2019, 2016, 2013, 2010 and lower versions of MS Outlook.

1. Launch Microsoft Outlook on your system.
2. Click on File tab → go to Info → then Account Settings
3. Click on the Account Setting option.
4. In the Account Settings window, select the E-mail tab and Microsoft Exchange. The system displays the Change E-mail Account.
5. Now you need to click More Settings.
6. Here in Microsoft Exchange window, choose 'Advanced'.
7. After that click Offline Folder File Settings.
8. In the File field, enter the path of the OST file, and click 'Ok'.
9. The system names the OST file as Outlook.ost. click Ok Note: If a file with the same name already exists in the system, then you will be prompted for a new file name.
10. At last click on the Finish button.

The system will nicely recreate a new OST file that contains all the data of your corrupted OST file. You should only use this process carefully if your OST file is no longer usable. This method can help repair OST files, resulting in data loss. So try other methods.

Method 4. Disable Firewall & Anti-virus settings to Fix OST File

An activated antivirus setting can sometimes block the normal functioning of the MS Outlook device. In this case, you may have to disable the required settings and restart the system again. Sometimes this type of trick can also repair blocked OST files. If this method does not solve your problem, proceed to the next method.

Method 5. Launch Outlook in Safe Mode

The main reason for starting MS Outlook in Safe Mode is to avoid add-ins that may have caused errors. Open Outlook in Safe Mode is also an option to skip these errors. However, this command doesn't repair OST files; it provides access to inaccessible OST files. You can start Outlook in Safe Mode with this command: "Outlook.exe / safe."

Step 1: Go to the Start button and click Run

Step 2: Now a "Run" dialogue box will appear on the screen, type Outlook.exe/safe

Step 3: after that click OK to continue and your outlook will open in safe mode

Limitation of manual methods:

• These manual methods only repairs minor OST file corruption issues and cannot fully repair and restore corrupted OST files.
• The manual method does not guarantee 100% safety of data while performing the recovery process.
• It is a time consuming solution with complex procedure.
• To use manual process users require technical knowledge, as a minor mistake can ruin the whole recovery process.

Method 6: Use Professional Tool to Repair OST file

If you are still unable to recover your OST files even after using the above manual methods we discussed so far. We suggest you try a professional solution named Regain OST Recovery tool. This is a most reliable tool with an easy-to-use interface to recover corrupt OST files, and the best part of this utility is that a technical novice can also run it to repair OST files.

For the better understanding of the tool, let us view its following features carefully:

• Provides complete recovery of OST files data (Mail, Calendar, Contacts, Notes, Tasks, etc)
• Smartly converts OST to PST, MBOX, EML, MSG, Office 365, vCard, Zimbra Files, Gmail, Thunderbird, Windows Live Mail and HTML files
• It provides 100% guarantee to fix corrupt or inaccessible OST file within few minutes
• Helps users in recovering Outlook OST file with both High Level and Compressible Encryption
• Allows users to view recoverable OST files data in preview panel before the actual recovery
• During OST File recovery, it does not compel any size limit on OST files
• It perform fast scanning of OST files and even generates Log file of whole recovery process in which it record each and every points of actions
• This software is compatible with MS Outlook 2021, Windows 11 and all the earlier versions of Windows OS
• It comes up with a user-friendly interface and can be used by a non-technical person without any hassle

Final Conclusion:

In this post, I have tried to explain the five free manual methods for OST File recovery, however these manual methods has some drawbacks. Keeping in mind, this thing we have also discussed professional software for OST File recovery that works in efficient way and recover lost files without any data loss. You can choose any methods from the above to repair and restore lost OST files.

Learn How to Repair Outlook OST File Working Video – Watch Now!

Frequently Asked Questions

Q 1. How can I repair an OST file manually in Outlook?

Ans. You can repair an OST file manually by deleting the damaged OST and allowing Outlook to recreate it, or by using the “ScanPST.exe” utility.

Q 2. Is there any free method to repair a corrupted OST file?

Ans. Yes, you can try recreating the OST by removing the file and starting Outlook again. However, this only works if your data is still on the Exchange server.

Q 3. Can I fix a corrupted OST file without using any third-party tool?

Ans. You can try manual fixes like recreating the Outlook profile or using the built-in Inbox Repair Tool. But these may not work for severely corrupted or orphaned OST files.

Q 4. How to manually recreate an OST file in Microsoft Outlook?

Ans. Close Outlook, navigate to the OST file location, delete the file, and reopen Outlook. A new OST will be created if the mailbox is connected to the server.

Q 5. What are the limitations of manually repairing an OST file?

Ans. Manual methods cannot recover unsynced or orphaned data and may lead to data loss. For complete recovery, a dedicated Regain OST File Recovery tool is recommended.

Q 6. Why is my OST file not opening even after manual repair steps?

Ans. If manual fixes don’t work, the OST file might be severely corrupted. In such cases, try Regain OST Recovery Tool to scan and restore your Outlook data.

Q 7. How to restore emails from an inaccessible OST file manually?

Ans. Manual methods require Outlook and an active Exchange account. If not available, use Regain OST File Recovery Tool to recover emails without needing Exchange.

Q 8. Can I recover deleted emails from an OST file using manual methods?

Ans. Only if Outlook is working and the items are still in the “Deleted Items” folder. Otherwise, use the Regain OST Recovery Tool for deep-level recovery.

Q 9. What is the best way to repair a severely damaged OST file?

Ans. Manual methods may fail for heavily damaged files. In such cases, the Regain OST Recovery Tool offers a reliable solution to repair and restore all mailbox items.