OST File Is In Use and Cannot Be Accessed

Solve Error: “OST File Is In Use And Cannot Be Accessed” in Outlook

Last updated: October 13th, 2021 at 06:33 am

Facing any errror in Outook like- “OST File Is In Use And Cannot Be Accessed”? Then this blog is for you. To get an answer for resolving your query simply read this blog and apply the mentioned steps and simply reaccess your Outlook profile

Mostly while using the Outlook application for emailing and other works in a large organization users prefer to configure theirs with Exchange settings. In all editions (from older to newer versions) Outlook creates and uses OST files. In addition, the new version of Outlook by default creates OST files when users configure IMAP or Office 365 accounts.

Outlook data file (OST) that saves a copy of all mailbox items that are available on the server. This file type facilitates users for working and editing data in offline mode when there is any connection problem with the server. When Outlook again connects with the server, it automatically syncs/fetches data from the OST file.

But sometimes because of various reasons, Outlook faces problems and 0shows an error like this:-

The file username.ost is in use and cannot be accessed

Also Read:- How to Fix “Outlook OST File Size Not Reducing After Archiving” Error?

Reasons For Error “OST File Is In Use And Cannot Be Accessed”

  • Syncronization between Outlook account and server.
  • Using single OST file with multiple application
  • Network Connection slow or failure issue
  • Corrupt Outlook data file (OST)

Above mentioned and some other can be a reason in your case for facing the error “OST File Is In Use And Cannot Be Accessed”. Below mentioned some of the user’s queries who facing the same problem:-

User 1:- I have an Outlook profile which is configure with Exchnage settings. But before a week i have accidently lost the connection with server. After doing a great hardwork i have again made the connection of Outlook profile with Exchnage Server. But when i trying to open my previous OST file it showing an error “OST File Is In Use And Cannot Be Accessed“. Is there any solution available to sort out this problem.

User 2:- Me any one other person are using MS Outlook with Exchange Server from a network drive but now iam unable to acces my profile. When i am opening Outlook it automatically shows this “The file username.ost is in use and cannot be access“. Please help me to resolve this error to again use my account in Outloook application.

Free Methods to fix this OST File Is In Use And Cannot Be Accessed error

There can be various reasons that can obtain errors in Outlook or in OST files. Below mentioned are some of the fixes that users can try to easily resolve this Outlook error:-

  1. Try to connect with server again:- If you are facing this error because of syncronization problem with server, then simply try to again connect with server. If you still facinng the error simply reconfigure your account with Exchnage settings.
  2. Close other applcation that using OST file:- If you have Opened your OST file in other third-party applications, this can also create problem in Outlook accessing data from OST. The simple solution to this problem is close other applications that using OST file and restart Outlook application.
  3. Check Network Connection:- Poor and slow internet connection also makes a connection break problem with server. This is another one reason for the corruption error OST File Is In Use And Cannot Be Accessed. Check & configure your network setting try to again connect Outlook with server.
  4. Fix/Repair Corrupt OST file:- In most cases of corruption in Outlook the reason is corrupt or orhaned OST file. A corrupt OST becomes unreadable in Outlook when a user tries to open it. A free utlity scanPST.exe is available for user to resolve minor corruption probem from Outlook OST files. If scanpst doesn’t work then you can utilize the method of repairing OST files with automatic software or Convert OST to PST for reading data.

Best Solution to Resolve “OST File Is In Use And Cannot Be Accessed” Error

If you are unable to read OST file data and facing any error while accessing OST files an automated PassFixer OST Converter/Recovery Software can help you. This single software will easily allow you to view an OST file data without the requirement Outlook or Exchange Server environment. It supports opening a corrupt/orphaned/inaccessible OST file smart process. Also, to resolve the Outlook error “OST Cannot Be Access” you can take advantage of this software.

The process is simple, easily convert OST to PST and configure your profile again in Outlook, then simply import your OST file data from the resultant PST file data in your new profile. Below mentioned are the complete steps, follow them to resolve errors and access the OST file again in Outlook:-

Steps to Fix Error and Repair Outlook OST file:-

  • Download OST to PST Converter software of password in your machine then launch it to start repairing process.
Main screen OST Converter
  • Now to add OST files in the software hit on the “MS Outlook OST file” radio button.
single ost file selection
  • Choose any one from the options “Add Single OST file” or “Add multiple OST file(Batch)” then select the OST file from its location and hit on Next.
  • load all inner folders and items from OST file and get a live preview of all items.
scan/load OST file
  • Make selection of required folder then hit on Convert.
preview OST emails
  • Now after previewing all items from OST file, Export/Save all OST items to new PST file. For this from the conversion options click the radio button “Export to PST“.
OST Conversion options
  • Apply mail filtering and click on Browse to select destintaion path for saving resultant files click on Convert.
Convert OST to PST
  • Software will start the OST to PST conversion task and after this you will get a new PST file with all your OST file content.

Now configure a new account in Outlook and import your newly created PST file in it and easily resolve “OST File Is In Use And Cannot Be Accessed” error.


There can be a lot of reasons for “OST File Is In Use And Cannot Be Accessed”. In most cases, the error comes when there is a connection problem with the server or when OST file is in use with any other application. If the reason is this the manual can be helpful. But if a corrupt Outlook data file is the reason for the error user should use the eSoftTools OST Recovery tool. This tool will help to open orphaned OST files and get data from inaccessible OST files.

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