I just got a new computer with Windows 10.  I have my old computer and have tried exporting from that and importing this into Windows 10. I have had NO success whatsoever.  I had a mobile computer repair guy come out and he had no success either. 

One problem making it difficult is the size of the file, which is quite large.  I got to 9 Gigabytes once and ran out of space.  what would probably be the easiest method would be able to copy from Windows  7, all files associated with mail messages and then copy that to Windows 10.  I saw one post that alluded to that but it was a little too complex to follow.

Is there any relatively simple way to do this.  I have switched systems in the past, also with problems but nothing of this difficulty.