Outlook Data File – The file C:\Users\<username>\AppData\Local\Microsoft\<username>\username.ost is in use and cannot be accessed. Close any application that is using this file, and then try again.

If you receive message Something is wrong with one of your data files and Outlook needs to close, when opening Outlook email client, see this post.

Your Outlook Data File is composed of a file header, located at the beginning of the document, and the actual data that makes up your personal folders. Contained in the header is information about the ...

An Outlook Data File (.pst) file is a copy of the information in your Outlook account (including, but not limited to, emails, contacts, and appointments) stored on your local device.

When Outlook continually looks for data file errors, that's because Outlook believes there is a problem. However, to repair any errors, the data file -- more specifically the Outlook .pst file -- ...

Q: I have a recurring problem with Microsoft Outlook. When I close it before shutting down my computer at night, everything seems fine. But when I try to open Outlook the next time, I get a pop-up ...

Here is how to save and restore your Microsoft Outlook PST and OST files with Recovery Toolbox for Outlook.

What is a PST File? The PST File of Microsoft Outlook is a useful application that allows the storage of Outlook emails for both received and sent emails in the hard drive of the computer.

Since the release of Microsoft Office 2007, all Outlook contacts are stored in a PST file. Copying your Outlook account's PST file to another computer or drive is important so you have backup copy all ...

Bruce Hillyer is moving to a new PC. He asked about bringing his email, contacts, and appointments from Outlook on his old PC to Outlook on his new one. If you use Windows’ Easy Transfer tool, the ...