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Install the latest updates for Outlook in the user's systems.<br />
<br />
Also,Please check the below:<br />
<br />
1) Create a new user outlook profile and check<br />
2) Create new windows user profile and check<br />
3) Download offline address book and GAL manually<br />
4) Remove the cached exchange mode &nbsp;and close outlook and enable it under account settings in outlook &nbsp;and Check.<br />
<br />
Let us know if you have taken all these steps...
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I have an environment which runs Exchange 2010 and outlook 2003, every now and again I get users that report to me their outlook has stopped working. We run a roaming profile environment and the error message I am getting when starting outlook is outlook.ost or pst is invalid, you then click on OK and outlook immediately shuts down. To fix this I have been resetting the roaming profile and deleting the local profile which is also created on the machine, then re-configuring outlook to point to the exchange server however it keeps coming back and I have had to this three times for one user. Any ideas anyone?
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I have an environment which runs Exchange 2010 and outlook 2003, every now and again I get users that report to me their outlook has stopped working. We run a roaming profile environment and the error message I am getting when starting outlook is outlook.ost or pst is invalid, you then click on OK and outlook immediately shuts down. To fix this I have been resetting the roaming profile and deleting the local profile which is also created on the machine, then re-configuring outlook to point to the exchange server however it keeps coming back and I have had to this three times for one user. Any ideas anyone?


Install the latest updates for Outlook in the user&#39;s systems.

Also,Please check the below:

1) Create a new user outlook profile and check
2) Create new windows user profile and check
3) Download offline address book and GAL manually
4) Remove the cached exchange mode  and close outlook and enable it under account settings in outlook  and Check.

Let us know if you have taken all these steps...

Outlook 2003 - outlook.ost invalid

Microsoft Outlook is a personal information manager from Microsoft, available as a part of the Microsoft Office suite. Although often used mainly as an email application, it also includes a calendar, task manager, contact manager, note-taker, journal, and web browser.

Outlook

Exchange is the server side of a collaborative application product that is part of the Microsoft Server infrastructure. Exchange's major features include email, calendaring, contacts and tasks, support for mobile and web-based access to information, and support for data storage.