Outlook express stores the address book in a windows address book file. These have a WAB file extension. Locate the address .wab file on your old computer and put it on a USB disk to transfer to you new computer. In the new computer type "contacts" without quotes into the search box on the start menu and press enter. In The windows contact pane that appearsselect import from the top row and follow the prompts to load your wab file. Then make a couple of changes to Thunderbird as I discuss here http://thunderbirdtweaks.blogspot.com.au/2013/12/windows-contacts.html to have the windows contacts appear in Thunderbird.