Outlook files are coming up as .ost instead of .pst

Posted on 2013-09-20
Medium Priority
Last Modified: 2013-09-23
I have a user that has a laptop.  A new hard drive was installed.   When we pull down this users back up and go to their outlook, the files have .ost extensions instead of .pst.   We cannot import the file with this users email.   I read that the same account has to be installed in Outlook to be able to open this backup file.   Is that true, and how do I import through Outlook, there is no choice to import a .ost file.   It is Windows 7 with Outlook 2010.
Question by:syssolut
LVL 22

Assisted Solution

by:Nick Rhode
Nick Rhode earned 400 total points
ID: 39509201
In order to open the .ost file you have to be logged in with the original account the .ost belonged to.  Then you can open outlook and do an export to .pst to extract the data.

There are security measures in place but you cannot just convert it unless you use a 3rd party software.
LVL 37

Assisted Solution

Kimputer earned 800 total points
ID: 39509395
Are you sure you even need to access the content ? These files are just cached from the server. (see http://office.microsoft.com/en-us/outlook-help/introduction-to-outlook-data-files-pst-and-ost-HA010354876.aspx)
Unless your server died, with no backup, I don't see why you need to spend time on these ost files.
LVL 14

Accepted Solution

btdownloads7 earned 800 total points
ID: 39509418
Ost files are used by Outlook if the user was connected to either an Exchange server, or an IMAP server. Unlike PST files, they are just offline caches, and Outlook can't open then directly. If you need to get data out of them, you'll need to get a 3rd-party program that extracts the data out of the OST file and creates a PST file for you.

If you just want to look at the data without recovering it, you can use this free viewer: http://www.nucleustechnologies.com/ost-viewer.html.

But if you do need to recover it into a PST, here are a few programs that you can buy:

Author Closing Comment

ID: 39514810
The user does have an exchange server and was all set when connected to that server.   Thanks

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