My colleagues computer suddenly crashed yesterday and it wouldn't restart without a system restore.

Now when we try to open up Outlook it says that you must connect to Microsoft Exchange at least once before you can usse your Outlook Data file (.ost)

Also The PC has lost the trust relationship on the domain

We have exchange 2010 and the servers OS is Microsoft Windows Small Business Server 2011 and the Client PC is running off of Windows 8.

Can you please help me resolve this issue?

kind regards

Steve Bradshaw

steve.bradshaw@eunisure.co.uk

It might be possible that the MAPI key (which enables Outlook to synchronize with Exchange) has been deleted due to the System crash. So, in order to establish the connection, you need to Reconnect the OST file to the original MAPI profile and then reconnect then MAPI profile to Exchange Server. 

If the above method fails to resolve the issue, then the best option for you would be to take the help of any professional OST to PST Conversion Software, which will help you to Extract data from your OST file and convert it to PST file which you can import back to your Outlook to establish the connection with Exchange Server again.

You can check this presentation for more info.