The best way to perform this conversion is by using a tool that automatically preserves the attachments along with the email messages. After converting, you should open the new PST file in Outlook and randomly check some email messages to make sure the attachments were properly preserved. DataVare MSG Converter is a simple and safe solution for performing this process. This program converts MSG files to PST format while maintaining all of the original attachments and folder structures. A free version is available for you to use so that you can try out the features of the utility before buying it.