Wednesday, February 8, 2012

Recovering Outlook data post OST file corruption

It is quite troublesome when Oulook freezes or doesnot open and all the data becomes inaccessible. Everytime an attempt is made to access the OST file data, certain error messages are encountered. Outlook OST file becomes inaccessible in the following scenario when it gives the following error message:

Event Type: Information
Event Source: Outlook
Event Category: None
Event ID: 30
Date: 5/1/2012
Time: 5:43:37 AM
User: N/A
Computer: Name
Description: The store C:\Documents and Settings\user.domain\Local
Settings\Application Data\Microsoft\Outlook\outlook.ost is being reconciled
with the indexer for the following reason: Non-matching max change numbers.


The user will not be able to access his Outlook OST file no matter how many times he tries to open it. Each attempt would result in the same aforementioned error message.

Cause:

OST file corruption accounts for this error and renders all the cardinal user data stored in that OST file as inaccessible. OST file corruption can result from myriad factors such as:

1.Incorrect file system recovery
2.Attack by virus or a malicious software
3.Abrupt Outlook termination
4.Dirty shutdown or power failure
5.Synchronization error
6.Network connection failure


Solution:

If the OST file is severely corrupt and is not required, then it can be deleted and a new OST file can be created by following these steps:

Step1- Quit MS Outlook.
Step2- Rename the existing OST file.
Step3- Restart MS Outlook in offline mode.
Step4- The following error message comes up:
"The file "C:\Exchange directory\file name.ost could not be found"
Click OK.
Step5- In the Offline Folder File Settigs dialog box, click OK.
Step6- You will receive this error message-
"The file c:\Exchange directory\file name.ost could not be found. Would you like to create it?"
Click Yes.
Step7- MS Outlook will start in online mode. Click Tools-> Synchronize-> All folders.

This way the newly created OST file will get synchronized with the Exchange Server and the user can resume working with the new OST file.

If the OST file contains precious data and can not be deleted then one needs to overhaul the corrupt Outlook OST file to recover vital data such as emails, attachments, contacts, calendar, appointments, jounals, tasks, To-do lists and notes. OST file can be repaired using “OST Integrity Check Tool” which is a free utility by Microsoft. Scanost.exe is able to repair the OST file and all the data is recovered. However, Scanost is not very efficient in repairing severly corrupt/damaged OST file. If you are in the same spot, then the only resolve is to convert OST to PST.

An adroit utility to convert OST to PST is “OST to PST Converter”. This powerful software is compatible with MS Outlook 2010, 2007, 2003, 2002 and 2000. It is a commercial OST Recovery tool that can create a new usable PST from the corrupt OST file while preserving the formatting from RTF and HTML messages.