Resolve Hotmail.ost Cannot be Accessed Error in MS Outlook Manually

Are you one of them who are looking for a solution of “Hotmail.ost cannot be accessed error”  in MS Outlook. If yes, then all your problems are going to be resolved here. But directly jumping to the solution will be the incomplete information. Therefore, before discussing a solution for Hotmail.ost cannot be accessed with MS Outlook, a brief introduction of OST file is discussed.

Hotmail.ost cannot be accessed error

Introduction on Hotmail.ost cannot be accessed error

At the organisation level, the OST file is one of the important files for the users who are not dependent only on a single type environment. Microsoft Outlook uses client-server environment when works with Exchange Server. In addition, to provide a business continuity when a user required to work offline, a cache replica of the respective mailbox is created. Moreover, the OST is created when a cache mode during account configuration is enabled.

Use of OST File

Apart from all this, OST file is not only created in the case of Exchange Server. However, when a user uses Exchange Account, everything exchange through it is first delivered to the server mailbox. Its copy is then stored in the OST file as the cache copy and mailbox sync together. For example, when a user configures the Hotmail account in the MS Outlook, an additional plugin, i.e. Microsoft Outlook Hotmail Connector is needed. After configuring a Hotmail account, MS Outlook generates an OST file to save all emails, calendars, contacts, and notes items, etc.

Due to this a user can easily read and view this OST file even when there is no internet connection. But sometimes user get an error message of Hotmail.ost cannot be accessed in Outlook. To solve this user first understand the reason behind it to fix it

Error Message Related to Hotmail.ost File

Malfunction or problems are likely to take place where there is a connection is used. Thus, one such case is explained below that has a Windows 7 local system, which is with Microsoft Outlook 2007 configured using Outlook Connector.

When the connection first established it works fine and everything is in proper synchronisation. However, as some little changes are made, it leads to the following error:

Manual Solutions to Resolve the Hotmail.ost is Not an Outlook Data File Errors

Solution – Hotmail.ost Cannot be Accessed Error in MS Outlook

Sometimes users try to change the folder name or make some changes to the configured account name This can help them in ending the Outlook to work with Hotmail with the respective “Hotmail.ost cannot be accessed” issue. Even user try to delete and recreate the configured profile, modifying or compatibility may fail sometimes, However, the two solutions that have the highest chance of providing successful results are discussed below:

Renaming & Re-synchronizing

One thing that a user can do is rename the already existing OST file and after that try to sync it back. It generally works in many cases. It is the recreation of the OST file, that somehow regenerates the sync between Hotmail and the file.

Using Scanpst.exe Utility

Microsoft Outlook keeps on generating an OST file every time, it will surely have recognised the OST file it created automatically at first, which leads to the discussed issue. One can use the Inbox Repair Tool rendered by Microsoft Outlook to fix or repair the OST file. However, the tool works with both OST and PST file. After that, use the backup file (.bak file) created for the OST and rename it to .ost from .bak. Then, start the Outlook and confirm if the sync works properly or not.

Using Inbuilt Tool and synchronisation method, the user can try to fix Hotmail.ost cannot be accessed error. Still, an error arises then the user can go for alternative methods.

Why Manual Method Fails?

The above discussed manual approaches are not the best way to resolve Hotmail.ost cannot be accessed error. However, there are some situations when the manual solutions may fail and all of them are discussed below:

  • Renaming and using scanpst.exe is not the full proved solution because of both works in only minor level corruption. In the case of highly corrupted OST file, it generally fails.
  • A user needs to be technically strong to use the above discussed manual procedures.
  • There might be the loss of data while using scanpst.exe to repair OST file in MS Outlook.
  • The manual procedure is a little bit complex and time to consume to resolve OST file related issues.

Effortless Solutions using OST to PST Converter

There are various situations due to which manual procedure to resolve the Hotmail.ost cannot be accessed error failed. However, if a user wants a guaranteed and direct solution then, want to convert OST file to PST Outlook using a trusted third party tool available online i.e. OST To PST Converter. The tool is specially designed to resolve all types of OST file related issues and export them to PST format. Moreover, the software provides an easy user interface that even a novice user can also use it without any issue.

Apart from all this, the converter also maintains the original formatting and integrity of data. After repairing the OST file, the tool saves it as PST file that can easily be accessed in MS Outlook. Moreover, the software is compatible with all versions of MS Outlook and Windows operating system.


The Hotmail.ost cannot be accessed error is either a result of a technical error or repeated regeneration of OST file. Therefore, most of the users are facing this same error and not able to resolve it easily. Thus, to resolve such OST file issues two different manual solutions are discussed that a user can use. However, manual approaches may fail sometimes. Therefore, in order to have a one-stop solution, a user can go for a third-party tool as suggested above to fix the error of Hotmail.ost cannot be accessed error through a converter that will provide a guaranteed solution.

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