Home » Blog » MS Outlook » Resolve Outlook is Using an old Copy of Your OST Error Easily

Resolve Outlook is Using an old Copy of Your OST Error Easily

Published By Nilesh Kumar
Debasish Pramanik
Approved By Debasish Pramanik
Published On January 25th, 2024
Reading Time 4 Minutes Reading
Category MS Outlook

It is such a quite annoying thing when you try to access Outlook and an error comes up and it becomes unable to access the Outlook as all of your mailbox things are going to be inaccessible to you. One of the often occurring errors is “Outlook is Using an old Copy of Your Outlook Data File (.ost)”.

This error indicates that the Outlook OST file got corrupted because of improper synchronization methods or some other reasons conjointly like threat virus, package crash, improper up-gradation of Outlook application because of that OST files become inaccessible.



Important Note: In case your OST file is inaccessible and you want to access and recover the mailbox data then the user can take the help automated solution.


Download Now Purchase Now

Solve Outlook is Running an old Copy of Your OST Error

Solution 1: Delete The OST  File To Resolve This Issue

The first solution to this problem “Outlook is using an old copy of your OST file” is to delete the corrupted OST file from the directory But, before deleting OST files, you would like to unhide the files. Version to version, the unhiding method is totally different. First, let’s discuss the strategy to seek out the hidden file.

In Order to Delete the OST File Follow These Steps:

Outlook OST file could be a hidden file. So first, we have to unhide the corrupted file before deleting it. Once making the files unhide, you are able to browse the hidden files.

Now, follow the below steps:

Make Visible OST Files

For Windows 7:

  • Click on the start button >> File menu.
  • Then, choose the Organize option and then select the Folder option.
  • Now, click on the Search options and move to the view tab option.
  • Select the Show hidden files option to preview the hidden files then select the folders and drivers option.
  • Uncheck the checkbox of hiding extensions for well-known file varieties.
  • Finally, click on the OK option.

For Windows 10:

  • First, launch the File, Explorer.
  • Then, choose the view option.
  • Finally, opt for the File name>>Hidden items.

After unhiding the hidden file, to delete the OST file you must go through these steps:

1) Open This PC or File explorer

2) Navigate to C:\Users\AppData\Local\Microsoft\Outlook

3) Delete all the corrupted OST files.

4) Make sure not to delete any file with the PST file format.

Now, Restart Outlook

But, there might be a prospect that the error is not mounted. Check the error “Outlook is using an old copy Outlook file (OST)” still seems or not. If not, then follow the steps to delete the corrupted OST file.

  • Run control panel>>Mail item
  • Click on Show Profiles>>choose your Profile.
  • Click on the Email Accounts
  • Hit on View or change existing e-mail accounts option, then click Next
  • Now, move to Microsoft Exchange Server Account and choose change
  • A window will seem with Mailbox server and Username; click on additional Settings
  • In the Microsoft Exchange Server panel, click on the Security tab
  • Select encrypt data between Microsoft Office Outlook and Microsoft Exchange Server check box, then click OK
  • Once you complete these steps, the error message “Outlook is using an old Copy of Your Outlook file (OST)” ought to be mounted.

Smart Solution For Outlook is Using an old Copy of Your Outlook Data File (.ost)

In case you are still facing the issues then the user can take the help of OST to PST Extractor Application. By using this the user can save the inaccessible OST file to PST file format. After saving the data the user can easily import this PST created from OST to Outlook Application. Also, this software is compatible with Outlook 2019 and its below version. To know more the user can try the free demo version of this application.


There are several problems that can occur in the OST file and it leads the users and organization into trouble in accessing the Outlook and it becomes necessary to recover the OST file.

Hence, In this blog, we have discussed how to fix Outlook Using an Old Copy of Your Outlook Data File (.ost). The user can try manual ways to resolve this issue, but if you failed, then taking the help of an automated solution is the best way to tackle this problem.


By Nilesh Kumar

As a Chief Technical Writer, I know the technical issues faced by home and professional users. So, I decided to share all my knowledge via this blog. I love to help you with challenges while dealing with technical jargon.