My hard disk had a problem and I had to back up my data in another hard disk. Once I got a replacement, I copied back my data. On opening my mails, I noted all my .PST files had changed to .OST and thus I was unable to open them. I get an error " The file you chose is not an outlook data file. You must select a new file of this type. How do i open this? Do i need to convert the .OST to .PST?
My machine is running on Windows 7 and Outlook 2007
Software/Hardware used: Windows 7 and Outlook 2007