How to locate, and delete, an OST file in Outlook

Within Microsoft Outlook, an OST file is the abbreviated name for offline Outlook data files. These files are designed to, in the words of Microsoft themselves, “Store a synchronised copy of your mailbox information on your local computer”. OSTs are there to ensure you the usage of your files if you happen to need access to them when offline, such as if ever you’re on a flight.

Sometimes though, you may need to delete an OST. Perhaps it’s to increase storage space, and there will be some files that you haven’t needed to access for some time. In order to locate and delete any OST files, you will need to access your Outlook account settings via the desktop version of Microsoft Outlook.

Now, it is important to note that following this process means you will have to follow the desktop version of Outlook. So, instead of accessing your inbox via your preferred browser, as you normally would, you need to access the application version that you can install onto your computer.

As is the case with every blog, there will first be a step-by-step guide to the process, before taking a deeper look into it via a thorough walkthrough, with accompanying screenshots for assistance.

Step by step: locate and delete an OST file in Outlook

  • Open the desktop version of Microsoft Outlook.
  • From the open document, click ‘File’.
  • Click the box, under the headline of ‘Account Settings’.
  • After opening the dropdown menu by clicking said box, click ‘Account Settings’.
  • From here, open the ‘Data Files’ subsection.
  • Click ‘Open File Location’ to open your files.
  • Locate the file you wish to delete and right click on it.
  • Select ‘Delete’.

Don’t worry if this isn’t enough information for you to go on. As already mentioned above, following this step-by-step is a further detailed discussion of the process.

Detailed breakdown: locate and delete an OST file in Outlook

First, you will want to open the desktop version of Microsoft Outlook. Again, it is important to note the difference between this version, and the browser version, as these steps can only be followed on the desktop model of Outlook.

In order to find the desktop version of Outlook, you can do it one of two ways. You can search for the version manually, scrolling through the files you have. This, however, may prove timely and would definitely prove tedious. Instead, you should search for it, in the search bar at the bottom of your screen, within your navigation bar.

After searching for the application (in the box marked with the number 1), open Microsoft Outlook (Number 2 on the screenshot).

After opening Outlook, you will want to find the File option within the application. This can be seen in the bar at the top of your screen, above your inbox. It’s been highlighted below.

After clicking File, you will be brought to a new menu, populated with numerous settings, as thus:

On this menu, you will want to look at the Account Settings section of options. You will want to click the box to the left of the body of text, the one highlighted in the image above. Doing so will open a small dropdown menu. On this menu, you will want to click the first setting you’re presented with, titled ‘Account Settings’ once more.

Clicking this will, once more, open another menu with its own options for you to browse through. Here, you will want to access the ‘data files’ tab, which has been emboldened by the red rectangle in the screenshot below:

Clicking the Data Files tab will open yet another section of your settings. Below the main navigation bar of the several types of settings, will be other options for you to browse. After clicking onto Data Files, you will want to look at the row of choices just below these headings, and select ‘Open File Location…’, which has again been highlighted below.

Clicking this will open a selection of files, in which are your OST files. The screen you see now should look like this:

Now able to browse through your OST files, you will be able to choose the one(s) you want to delete.

In order to access the delete option, the process is far quicker than the above one to initially locate the files. Simply right click on the file and click ‘delete’.


Do this with as many files as you desire, and you successfully will have located, then deleted, your OST files!

Thank you for taking the time to read this blog, I hope you found it as helpful as you wanted it to be! As always, if you run into any issues with this process, or simply wish to tell us how you found it, then please do not hesitate to get in touch with our team.

Below are links to a couple of articles linking to OST or PST files, issues you may have with them, and how to resolve them.

How to delete a corrupt OST file: Outlook – Business Tech Planet
(A piece that looks at deleting corrupt OST files via the File Explorer)

Receiving Duplicate Emails in Outlook – How to solve a corrupt PST file – Business Tech Planet
(A piece that explores the possible use of scanpst.exe to solve a corrupt PST file issue)

Michael Fontana

Michael Fontana has been the managing director of telecoms and MSP Optionbox for over a decade and has worked in various telecommunication roles over the last 20 years. Michael has been involved in many exciting projects, such as co-founding telecoms and IT businesses and has now built up a team of more than 15 staff, serving over 300 clients nationwide. With a wealth of experience in IT and a passion for technology, Michael is now helping BTP to produce the highest quality guides on the internet. You can connect with Michael on LinkedIn.

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