Repairing an Offline Folder file (.ost)

Posted by Jonh Wednesday, April 9, 2008

You may want to scan and repair your .ost if you:
• Encounter a large numbers of conflict items.
• Cannot open particular Outlook items when offline.
• Receive unexpected synchronization error messages (as shown in the synchronization log in the Deleted Items folder).
• Receive the message:
Unable to expand the folder. The set of folders could not be opened. Errors could have been detected in the file drive:\Documents and Settings\user\Local Settings\Application Data\Microsoft\Outlook\Outlook.ost. Quit all mail-enabled applications, and then use the Inbox Repair Tool.
Note The file path specified in the message may vary depending upon the operating system you are using on your computer.
In addition, you might be able to open folders in the .ost but get synchronization error messages that do not go away. This happens when a single e-mail message is damaged and the synchronization process cannot correct it. You can use the OST Integrity Tool to fix damaged messages or to move them so you can synchronize successfully.
Important: You may need to run scanpst.exe (see the first procedure above) first if the OST Integrity Tool cannot open the .ost file.
To scan and repair the .ost file
1. Close Outlook.
2. On the Start menu, click Run.
3. In the Open box, type
drive:\Program Files\Common Files\System\Mapi\LocaleID\scanost.exe
where LocaleID is the locale identifier (LCID) for your installation of Microsoft Office. For example, the LCID for English (United States) is 1033. For a list of LCIDs, see Microsoft Office Help.
4. Click OK.
5. Click either Scan all folders or Choose folder to scan. If you click Scan all folders, this may take several minutes.
6. Select the Repair errors check box.
7. Click Begin Scan.
Details of actions performed during the scan and repair are saved as a message in your Outlook Deleted Items folder with the subject "OST Integrity Check."
If the Offline Folder file cannot be repaired, you can disable it and create a new one.
To disable the .ost file and create a new one
1. On the Tools menu, click E-mail Accounts, click View or change existing e-mail accounts, and then click Next.
2. In the list, click Microsoft Exchange Server, and then click Change.
3. Click More Settings.
4. Click the Advanced tab, and then click Offline Folder File Settings.
5. Click Disable Offline Use.
6. In the File box, type the path to the file you want to use as the new .ost file. The default file name is outlook.ost. If this file name already exists, you are prompted for a new name.


  1. Alex Says:
  2. I heard about not bad application-ost repair, is an easy-to-use program, that permit to repair *.ost files, when they are corrupted or not accessible by Microsoft Exchange Server,restore your personal data,you can convert your *.ost to a *.pst file, that can be easily opened by any mail client, compatible with Microsoft Outlook, it can be also forwarded to any PC and opened under another user account,can extract your files separately, it means, that the program will create a folder, where all of your contacts, emails and tasks are stored in *.eml, *.txt and *.vcf formats.

  3. Alexis Says:
  4. Know good tool which works with outlook files-open .pst file,tool is free as far as I know,program works under Windows 98, Windows Me, Windows NT 4.0, Windows 2000, Windows XP, Windows 2003, Windows Vista and all supported versions of Microsoft Outlook,will work fine for both experts and beginners, there are no any extra settings,program repairs more data, than other services, owing to its unique data recovery engine, developed by our engineers,can easily retrieve your mails, that could be lost without this program,will make a decision, which emails can be successfully retrieved from your mailbox,can preview analysis results during the next step, where you will be redirected after the analysis,retrieve all emails as a set of files in *.vcf, *.txt and *.eml format, that will be stored in any place you like,convert all documents to a file of PST format, this file can be opened offline by any email client.

  5. Alex Says:
  6. So,I heard about one tool-can t view my inbox messages in microsoft outlook.At first time the tool could help me very fast and absolutely free.Moreover program helped my friends too and not once.I am lucky))

  7. Vikram Bisht Says:
  8. Recover Exchange OST as PSTto recover all the damaged and lost OST data. Exchange OST as PST converter works to get away from the situations like Exchange Server crash, virus or Trojan infections, storage device failure, hardware crash etc.

  9. Jack Says:
  10. scanost.exe is the built in tool in Outlook and is also known as Integrity Check tool. But this tool does not resolves the issue in every case of corruption. it is always recommended to backup the .ost file before using this tool and if scanost.exe fails to resolve the issue you may give a try to third party ost recovery tool that converts ost to pst file and the resulting pst file can be directly imported in Outlook

  11. Unknown Says:
  12. Outlook ost converter tool is very helpful in recovering corrupt ost file. Such tools convert ost to pst file and then the pst file can be accessed directly with Outlook

  13. Unknown Says:
  14. Outlook ost converter tool is very helpful in recovering corrupt ost file. Such tools convert ost to pst file and then the pst file can be accessed directly with Outlook

  15. Anonymous Says:
  16. Checkout one of the best OST to PST Converter software, which i ever used :

  17. Annie Says:
  18. Do you have info about a very convenient and reliable PST Recovery computer software to recover outlook PST, email, calendar, tasks, contact list and also other PST files items.
    recover deleted pst file

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