Snipergod87 :
You can't you need it to be a .PST file. A .OST is Offline Storage file.
<snipped>
Thanks for your response. I have read that page earlier also but this ost thing is a little confusing for me. In the past I have used pst files only.
The reason I was trying to open ost files was because I had to reinstall Office a few times after resetting Windows 8 and therefore I have some "old" ost files.
Is it safe to delete old ost files or might that result in losing older email messages?
Thanks!