Transfering email folders in Live Mail to Outlook

I'm trying to copy my email folders, that have built up over the years, into a different system.

Currently they are on Laptop A,  in Windows Live Mail. I would like to transfer them to Laptop B, in Outlook

I've got to the stage, on A, of File/Export Mail/Export Messages/select format to export to.

I then get the message "Windows Live Mail (not responding)". The system then restarts and puts me back to square one.

Is there a simple way to achieve what I'm trying to do?

When I've accomplished this I can retire Laptop A.