Tuesday, April 5, 2011

Tips to Solve Error: '.ost is already in use by the maximum number of applications'

An Outlook Offline Folder (.ost file) allows users to access Exchange mailbox data even in offline mode and then synchronize the changes at next secure connection with Microsoft Exchange Server. This efficiency of Outlook is quite useful in scenarios of low or inappropriate connectivity. But similar to other files, an OST file can also get corrupt. Such situations necessitate that you either restore from backup or use a Convert OST tool that retains the capability of converting a corrupt OST to PST file and thus recover ost file.

Following is an instance of such probable events in Microsoft Outlook. Consider a user using Microsoft Outlook 2003. At one point of time, it might come across the below error message:

The file OST_File_Path\outlook.ost is already in use by the maximum number of applications. Close some of the applications, and then try again.”

Outlook user receives this error repeatedly.

Cause :
The above error is encountered due to following possible reasons:

  • As suggested by error message, Outlook OST file is being accessed by different applications.
  • You are trying to access a corrupted OST file.

Solution :
Below are the solutions to the above discussed issue:
  • If the file is opened by various other proceses, you need to close those programs. Restarting the computer should completely resolve this issue, if this is the only reason.
  • Microsoft Outlook installation includes a utility called OST Integrity Tool that can be used to correct corruption problems with OST. To run the tool, follow the below steps:
  • Exit Outlook.
  • Click Start | Run and type the following path in open box:

drive:\Program Files\Common Files\System\Mapi\LocaleID\scanost.exe
Where, LocaleID is the local identifier of your MS Office installation.

  • Click OK and click 'Scan all folders'
  • Select 'Repair errors' check box and click 'Begin Scan'

If OST Integrity tool doesn't resolve OST file corruption, you need to use a third party tool that can repair and later Convert OST to PST. The file converted in PST can be directly used within Outlook. A Convert OST tool is easy to use and can run safe scanning procedures to extract data from Outlook offline folders.