Tips to open OST file

Can't open the OST file? You are not the only one. Thousands of users face similar problems every day. Below you will find tips on how to open OST files as well as a list of programs that support OST files.

OST file extension

File Name Outlook Offline Folder Format
File Developer Microsoft
File Category Misc Files

The OST file is supported on 1 operating systems. Depending on your operating system, you may need different software to handle the OST files. Below is a summary of the number of programs that support and open the OST file on each system platform.

Operating systems
  • 5
  • 0
  • 0
  • 0
  • 0
  • 0

What is OST file?

The file in the OST format belongs to the Misc Files category. The creator of this file is Microsoft. Misc Files consists of 6033 similar files. Outlook Offline Folder Format is supported by 1 operating systems. These systems consist of Windows, although it may occasionally be found on another system, it will be non-functional. The Microsoft Outlook application is recommended to open the file. It was released by Microsoft Corporation. This file type can also be opened by 4 other programs. Convert OST to PST, Outlook Recovery Toolbox, Advanced Exchange Recovery, Kernel for Exchange OST Recovery will apply when it is not possible to use Microsoft Outlook.

How to open OST file?

An often recurring problem with Outlook Offline Folder Format is that OST is not associated with the correct program file. Thus, when you open OST, the program selection wizard or some other program starts. This problem can be easily remedied.

The first thing you should do is just "doubleclick" on the OST file icon you want to open. If the operating system has an appropriate application to support it and there is also an association between the file and the program, the file should be opened.

Step 1. Install Microsoft Outlook

In this case, you should first verify that the Microsoft Outlook application is installed on the computer. To do this, enter the name Microsoft Outlook into the system search engine. In the absence of an appropriate program, its installation in the vast majority of cases will fix the problem. Below is a list of programs that support the file OST.

Step 2. Create association of Microsoft Outlook with OST files

If, despite the installed application, the OST file does not start in the Microsoft Outlook application, you must create a file association. It is most convenient to call the context menu with the right mouse button and select Properties. Information about the file and the program that the file is associated with are available here. Using the "Change" button we can set the program to handle this type. It may happen that in the next window there will be no appropriate program - however, this can be corrected with the "Browse" option where you should manually indicate the program location. Checking the "Always use the selected program ..." box will permanently associate the OST file with the Microsoft Outlook program.

Step 3. Update Microsoft Outlook to the latest version

If, however, after binding Microsoft Outlook with Outlook Offline Folder Format there were still problems, you should update the program to the latest version. This can be done using the application (if it provides such options) or from the Microsoft Corporation website and install the latest version.

Step 4. Check for the following problems with the OST file

Of course, it may happen that despite the above steps, the file still does not work. File problems can be divided into the following:

The OST file may be unusually small compared to the original file. Usually this applies to OST files downloaded from the Internet in case the download did not finish properly. The only repair option is to download the file again.
The most common cause here is computer viruses. A quick virus scan using an up-to-date antivirus program should clear up any doubts. If this is not possible, you can use the online scanner. However, it is important to scan the entire system, not only the file OST or the program directory. However, remember that not every infected OST file can be recovered, so it is important to take care of regular backups.
A typical compatibility error - the program does not support the older version of the OST file. On their websites, developers usually offer free solutions to such problems, e.g. in the form of a conversion program or an older version of the program.
There can be many reasons for this. Repairing is very dependent on the file type. Sometimes the program itself has options to repair the most popular OST file corruption. The easiest way is to restore the file from a backup, if there is one, or contact Microsoft
The program indicates that the file is encrypted or corrupted. The encrypted OST files cannot be played on other computers than the one on which they were encrypted, they must be decrypted before using on another device.
Some operating systems do not allow file operations in certain locations, eg in system directories or directly on the system drive. These directories are write-protected to them and it's very hard to fix this problem. It is best to move OST to a different directory.
This can happen on a file that does not support multiple access. You may find that another program you are using is preventing you from working with the file. Running programs (including those in the background) should be verified. If the error persists after closing other programs, wait for a while. Antivirus programs or a backup being made may lock the file for a while without the user's knowledge. If this does not work either, restart the device.