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How to Convert OST to PST ?

How to Open OST (Offline Data File) ?

This post will guide you to open a local client archive .ost file on your computer.

An OST is an offline folder file in Microsoft Outlook that is used with Microsoft Exchange Server. It is very helpful if you are using Outlook in an offline mode or if there are internet connectivity problems at your place. Working in an offline mode is, in fact, very similar to working with a mailbox on a server. The changes made in the offline mode are reflected when connection is restored and synchronization takes place. However, sometimes users need to access this OST file on a new machine/computer. Sometimes, these files can get corrupted due to various reasons and users want to open them anyhow.

Unfortunately, MS Outlook doesn’t provide any option to open an Offline Outlook Data File (OST) directly.  In these situations, when a user attempts to open/access OST file, the get some error messages like:

  • The file you chose is not an Outlook Data File. You must select a new file of this type.
  • Cannot open OST file. You must access Exchange at least once to use the OST file.

The above error messages appear each time when the users try to open an orphaned/corrupt OST file. To resolve the above problems and to open the OST file data, you will need to Convert OST to PST using a third-party application. Once, an OST file got converted to PST file, it can be easily imported into MS Outlook. Such third party tool employs advanced, yet safe mechanism to fix and convert OST file to PST. Once OST file is converted, the file can be opened in MS Outlook.

Mailbox Account Deleted: Convert OST to PST

To use the collaborative communication feature of MS Exchange server through MS Outlook, you must have a mailbox account on the Exchange Server. The user can gain access to the mails and other features through this account only. Each individual, connected to the Exchange Server, holds a personal mailbox account. The mailboxes are stored on the Exchange Server hard disk as file of e-mail messages. To access the mailbox, you need to clear some criteria such as account verification.

Now at the user level, there is a file called Offline Storage File (OST) which makes the user capable to work offline too. After you become online, you have the ability to synchronize the offline folders and information store of Exchange Server and all the changes are uploaded. This happens as this OST file is now converted to PST (Personal Storage File). The user can interact with the PST file and not with the OST.

The OST file is an exact replica of your mailbox on the Exchange Server and is updated during synchronization and as soon as you access the mailbox account, this is converted into PST as the storage location on your hard disk. To get access of the PST and to get the new and old mails, you need to log in with the correct user name and password.

Now what if the mailbox account gets deleted from the Exchange Server somehow? Then you can’t access your PST data even as now OST is unable to get converted.

This is the weird situation as now all the e-mails, contacts and rest other Outlook objects, containing the relevant information related to the business, can’t be accessed. The only solution to this problem is to have a tool which can convert OST to PST. These solutions come in the form of easy to use software. These software enable OST recovery for all the objects like e-mails, contacts, tasks, journal etc.

Advance OST to PST Converter is the ultimate software which converts Outlook .ost file to .pst file in the most effective manner. The software works efficiently in all the cases when the mail account has got deleted or crash of the Exchange Server itself.

The software performs OST recovery for encrypted as well as password protected files and for all the objects. This convert OST to PST utility is compatible with Outlook 98, 2000, 2002, 2003, 2007 and 2010. Providing the interactive user interface, the software supports Microsoft Exchange Server 5, 5.5, 2000 and 2003

How to Recover corrupt Outlook PST file by PST Recovery software

MS-Outlook e-mail application stops working or responding when PST file gets corrupt. Corruption not allows you to access mail-objects. Corruption occurs due to several reasons. These reasons are discussed in next section of article. For carrying out work with Outlook application, you have to first recover the PST file. You can use an inbuilt Inbox repair tool. But due to its limitation, sometimes PST file cannot be repaired by it. In such situations, third party PST recovery software can be used. Such third party software performs PST recovery instantly and makes all the data accessible.

Top most reasons for PST file corruption:

Reasons of PST file corruption includes hardware and software issues. Hardware and software issues can be further categorized. These are as follows:

Hardware reasons: Hardware reasons are the reasons when system hardware stops storing or moving data of PST file. The same also leads to PST file corruption. These reasons are:

1. Problematic networking device: PST file stored on a server computer cannot be accessed by client computer, then faulty hardware components may lead to corruption of PST file.

2. Power Outage: Loss of power supply may also bring PST file corruption.

3. Data storage device failure: If the Outlook PST file is stored on bad sectors of hard drive.

Software reasons: Behind PST file corruption, several software related issues are also responsible. These are as follows:

1. Wrong File System Recovery: While doing file system recovery, recovery cannot get properly exhibited, which in turns lead to PST corruption.

2. Fatal Virus attack: Some viruses are there that corrupts the Outlook PST file.

3. Abrupt exit of Outlook programs: Exit of MS-Outlook abruptly, directly corrupts the Outlook PST file.

4. Errors in Outlook programs: Errors in Outlook makes the Outlook PST file corrupt or damaged.

Above mentioned are the causes for PST file corruption. But PST file corruption can also be solved.

Know how to resolve the issue:

For repairing the corrupt Outlook PST file, an inbuilt Inbox repair (Scanpst.exe) tool can be used. The tool scans and repair PST file in most of the corruption cases. It cannot be used in all the instances of corruption.

For satisfactorily repair results, you can choose a third party PST recovery software. Such tools perform PST file recovery quite well. You can download a tool from an Internet. Such tools perform recovery of PST file by its own. You do not have to take some others help for using these software. You do not have to technically sound and no prior recovery experience is needed.

Outlook PST Repair is an authentic tool that gives quite good PST file recovery results. You can easily recover data of Outlook mail objects, like contacts, attachments, appointments, journal, tasks, events, and similar mail components. It recovers data in such a manner that overall data remains unaffected. The tool shows compatibility with Windows 7, Vista, Server 2003, XP, and 2000. Demo version of the tool can be used to preview the data stored in .pst file.
It supports all versions of MS Outlook i.e 2010, 2007, 2003, 2002, 2000, 98, and 97.

OST converter can be used to solve OST corruption issues

Offline mode of MS-Outlook allows you to access mail-objects without Internet connectivity. Working in offline mode has its own conditions. You cannot send e-mails in offline mode. Once, Outlook gets synchronized with Exchange Server. All the data of Outlook automatically gets synchronized. At times, OST file cannot be synchronized with Exchange Server. This mainly happens because of the following factors. These factors include, unavailability of Exchange Server, deletion of mailbox, fatal virus attack, and application errors, corruption of Outlook OST file. But such situations can be overcome by using some precautions. Otherwise, a third party OST PST converter tools can be used. Through, this you can easily convert OST data that is inaccessible into a accessible PST file.

Below discussed error message appears when you try to synchronize data of OST file, but synchronization remains incomplete. And, you receive an error message that looks exactly same as given below:

“Errors in background synchronization. In most cases, more information is available in a synchronization log in the Deleted Items folder.”

When a synchronization log is opened, the following information is seen:

“15:19:28 Synchronizing Mailbox ''
15:19:28 Synchronizing Folder 'Outlook Security Settings'
15:19:28 Error synchronizing folder
15:19:28 [8004060C-53F-0-550]
15:19:28 The OST has reached its maximum size. To reduce
the amount of data in this OST, start Outlook in offline mode, select some
items that you no longer need, permanently ( press SHIFT + DEL) delete
them, then re-sync this folder.
15:19:28 Microsoft Exchange Server Information Store
15:19:28 For more information on this failure, click the URL below:
15:19:28 Synchronizing Views
15:19:28 Done
15:19:29 Microsoft Exchange offline address book
15:19:29 Download successful”


Such kind of problem occurs when the size of OST file crosses or reaches the set size limitation. Due to exceeding size limitation, OST file gets corrupt. Due to corruption of OST file, all the data becomes unapproachable.


OST corruption can be avoided easily. For doing this, it is suggested to decrease the size of OST file. You can decrease the size of OST file, by following measures:

  • Transfer data of the OST file to a Outlook PST file.
  • Remove some data from the OST file.

After deleting or moving the data of OST file, try to compact the OST file. After the use of compact option, execute an OST Integrity check tool to scan and repair the OST file. After the execution of OST Integrity check tool, if you are still unable to synchronize data of OST file, then you need to perform OST to PST conversion with a help of a third party OST PST converter tools. But before using these tools, use all the inbuilt methods.

OST to PST Converter is a professional tool used to convert OST file data into a PST file. Unusable data of OST file becomes usable. The tool provides an option of restoring the data of OST file as PST file on any disk that can be detected with the help of a operating system. Advance scan is used, if by normal scan data of OST file cannot get recovered.

What to do when failed synchronization results in OST corruption in MS Outlook

Taking a practical situation, let us assume that you are working on MS Outlook 2000 in offline mode. You have to send some emails, which you have composed in the offline mode. You try to synchronize with the Exchange Server to send these mails. However, there are some problems because of which you are unable to send these emails.

You cannot even delete the OST file as then you would lose the important data that you created while in the offline mode.


The most possible cause of such strange but very common problem is that the OST file has corrupted or is damaged. Because of this, you are unable to synchronize with the Exchange Server.


There are the following measures that you should take in such situations:

Download and install hotfix: You should download and install a hotfix, Microsoft Office 2000 Service Release 1/1a (SR-1/SR-1a), recommended for Outlook 2000. With this upgrade, the synchronization process gets completed even after receiving a problem. The non-synchronized items get collected in the Corrupted Items folder.

Run OST Integrity Check Tool: You should run the OST Integrity Check Tool for Outlook 2000 that scans the OST file for errors and repairs them, if any. It does this by comparing the OST file and the user mailbox on the Exchange Server. If it finds any dissimilarity between the two, it tries to correct these.

Now, if you are unable to synchronize with the Exchange Server properly then the use of third-party OST-PST conversion tools becomes very obvious. Such non-destructive tools repair the OST file and rescues the data by converting the orphaned OST file to an equivalent and usable PST file.

The most efficient third-party tool that converts OST to PST file is advanced OST to PST Converter, which works on MS Outlook 2010, 2007, 2003, 2002, and 2000. Compatible with Windows 7, Vista, Server 2003, XP, and 2000, this converts OST to PST by recovering various Outlook objects like emails (with attachments), journals, tasks, calendar items, distribution lists, contacts, etc. Also, this OST to PST converter preserves the formatting of the messages during the OST-PST conversion.

Converting oversized OST to PST file in MS Outlook 2002

Are you using MS Outlook 2002 as your email application? Also, are you working on it in the offline mode? If the answer to both the questions is YES, then you should be careful about its usage as the OST (Offline Storage Table) file can become corrupt once it crosses 2 GB. In such cases, you should try to upgrade to higher versions of Outlook and/or repair the OST file. If the problem is not resolved, then you should use a third-party OST PST converter to recover the OST file and convert OST to an equivalent PST file.

Consider a scenario wherein you are working on MS Outlook 2002 in the offline mode. You are trying to synchronize the OST file with the Exchange Server. In this process, the size of the OST file exceeds 2 GB. After this happens, you are unable to add more email or other objects to the OST file. An error message is displayed, when you try anything of this sort, which is:

“Task 'Microsoft Exchange Server' reported error (0x00040820):'Errors in background synchronization. In most cases, further information is available in a synchronization log in the Deleted Items folder.'”


The root cause for this problem is that the size of the OST file has gone beyond 2 GB. Because of this, the OST file has become corrupt. In such cases, the mail delivery to the OST file stops. However, you do not get any error message suggesting why is this happening so.


To resolve this problem, you should upgrade to MS Outlook 2003 as this Outlook version allows to have more than 2 GB of OST file size and then try to repair the OST file using the in-built OST Integrity Checker tool. The OST file will be repaired once you use this utility.

However, if the problem is still persisting and you are unable to work properly with the OST file, then you should convert OST to PST file. As Outlook does not provide any in-built tool to do the OST-PST conversion, you should use a third-party OST to PST converter. Such read-only tools are completely safe in nature and do not effect the original OST file during the conversion.

Advanced OST to PST converter that converts OST to PST file by recovering OSTs files from all sorts of corruption. Specially designed to recover OST files created in MS Outlook 2010, 2007, 2003, 2002, and 2000, this OST to PST conversion software repairs various Outlook objects such as emails (with attachments), calendar entries, contacts, tasks, journals, etc. In addition, this convert OST to PST utility preserves the formatting of the HTML and RTF messages during the OST-PST conversion. It is compatible with Windows 7, Vista, Server 2003, XP, and 2000.

Related Post:

How to Resolve Outlook Error 0x00040820 message ?

How to Resolve Outlook Error 0x00040820 message ?

Suppose you are trying to synchronize the .ost file in Outlook 2002 with Exchange Server which has reached 2GB file size limitation, it may results in following error message.

"Task Microsoft Exchange Server reported error (0x00040820): Errors in background synchronization. In most cases, further information is available in a synchronization log in the Deleted items folder."

This problem is commonly known as oversized OST file issue. In a case when the ost file reaches its file size limit, you are unable to access all the emails and other data saved in the OST file. The OST files becomes inaccessible in Outlook 2002 and earlier versions, as soon as it reaches the size of about 1.82 GB. In this case you can take some precautions such as reducing the ost file size because MS Outlook and Exchange Server do not have any built-in tool or feature that can resolve the over sized ost file issue.


This error message occurs because OST file in Outlook 2002 and early versions has 2GB file size limitation


Follow any of below mentioned steps to resolve the problem:

1. Permanently delete all the unwanted items from the server based email folders.

2. Move data from any synchronized folder to a non-synchronized folder on the Exchange Server.

3. Move data from a synchronized folder to a personal folders (.pst) file, and permanently delete the data from the synchronized folder.

Run scanost.exe utility to remove the extra space created due to permanently deleted data. But if in case there is no extra space due to deleted items, the scanost.exe utility will not work.

Where to search for scanost.exe file: C:\ Documents and Settings\ username\ Local Settings\ Application Data\ Microsoft\ Outlook\ outlook.ost

It is not always possible to permanently delete items from your server mailbox, in such a case manually convert ost to pst file. Third party ost to pst converters are available to convert ost file to pst file, the resulting PST file can be imported to MS outlook directly. OST to PST conversion software uses advance scanning techniques to convert damaged or corrupt Outlook ost to pst file. Such tools are read only i.e. do not alter original ost file contents. OST converter Software supports MS Outlook 2000, 2002, 2003, 2007, 2010 and is compatible with Windows 7, Vista, XP, 2003, 2000.

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