Export emal from Outlook Express/Import to Windows Live Mail

I am trying to move my email from an old desktop, running Windows XP, to a laptop, running Windows 7.  I  exported the email from Outlook Express and confirmed that a .dbx file was created for each folder in Outlook Express.   I loaded Window Live Mail onto the laptop but when I try to import the email into Windows Live Mail, many of the folders do not get imported and so much of my email is missing.