Microsoft Outlook uses two file types for holding message, calendar, task and notes data: PST and OST files. PST files are created in the user's computer for non-Microsoft Exchange accounts, which ...

Mac OS X computers use a default application to open every file type based on its file extension. If you don't want to use the default application when opening a file, you can select "Open With" from ...

Breakthroughs, discoveries, and DIY tips sent every weekday. Terms of Service and Privacy Policy. Being unable to open files as usual is one of the most frustrating ...

When you double-click a file on your computer, Windows may launch an application to run or display the file. Windows knows how to do this because it maintains a list of known file types and the names ...

To improve security Microsoft Office prevents some previous versions of Microsoft Office file types should from being opened, without the help of Protected View in Trust Center. Microsoft Office comes ...