Which you need to know BEFORE you rebuild your PC. (So you can take a backup copy of it).
Not that obvious until you need to know where to find it:
HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem\Profiles\Outlook\9375CFF0413111d3B88A00104B2A6676
This is big news, particularly if you’ve ever tried to convert an OST file to a PST file.
… In order to facilitate interoperability and enable customers and vendors to access the data in .pst files on a variety of platforms, we will be releasing documentation for the .pst file format. This will allow developers to read, create, and interoperate with the data in .pst files in server and client scenarios using the programming language and platform of their choice. The technical documentation will detail how the data is stored, along with guidance for accessing that data from other software applications. It also will highlight the structure of the .pst file, provide details like how to navigate the folder hierarchy, and explain how to access the individual data objects and properties….
– Paul Lorimer, Group Manager, Microsoft Office Interoperability
(if you don’t know what an OST file is, see below)
There are four options, one of these below might work for you.
NOTE: This is a work in progress post. It will be updated when I learn something.
The OST2PST conversation method.
Sources:
MS Exchange Blog: OST to PST
Geeks To Go: Converting Outlook .OST files to .pst
This method may not work with Outlook 2003 or later OST files.
Modify the header file method
The type of Outlook file, whether it is a PST or OST, is stored in the header of the file.
It might be possible to modify the header, and open the modified file in Outlook.
The file format has been documented in “Personal Folder File (PFF) forensics” by Joachim Metz.
Compile and use the pffexport program method
“Extracts items from a Personal Folder File (OST or PST)”. See the libpff site.
Buy any number of commercial products method.
I’ve tried none of these. You are on your own.
| Product Name | Cost (in US Dollars) |
| Recovery Toolbox for Outlook | $50 –> $90 |
| Kernel Recovery for OST | $249 –> $399 |
| Recover Data for OST to PST | $99 –> $299 |
| Advanced Exchange Recovery | $250 |
| Quick Recovery for OST to PST | $129 –> $229 |
So what is an OST file then?
If you’re asking this question, you probably don’t need to know. 🙂
An Outlook Offline Storage Table (OST) file is a copy of your Exchange email account. This copy allows you to access your (offline) email while you are not connected to a network. Such as when you are travelling..
Update October 2009: Roadmap for Outlook Personal Folders (.pst) Documentation