Outlook works with two data files. .OST and .PST. I won’t go into details about what they do and the difference between them but what you should know is that an .OST file can be opened only by using the account that created it, this in most cases means only the computer on which the file was created.
For example, if you will leave your company and you will receive an .OST file from your IT dept. which contains the emails, calendar and so on you might have a hard time accessing the data inside from another computer.
In order to read the info inside this .OST file you will have to use a software to convert or read the data inside.
A free and useful such software is FREE OST Viewer and can be found here: http://www.freeviewer.org/ost/
Just download it, install it and then if you know the location of the .OST file point the software to it by using File and ADD/OPEN or just use search if you don’t know the location and your computer will be scanned for .OST files.
It’s pretty easy to use. I’m sure you will handle it.
However, any user get traped when their OST file is not working in Outlook. in that case user is looking for the solution to open OST file in Outlook on another computer. It can be simply done by converting OST file into PST format.
Read this article for the better solution to “How to Open OST File on Another Computer?“