You need to backup both your contact information and your mail.
Contacts: Open Outlook Express. Click on File, Export, Address Book. In Windows Live Mail (WLM), open the contacts folder. Choose Text File, comma delimited, Export, Browse to your My Documents folder and setup a Backup folder in that one. Choose that folder. Name that new folder. Now, give the file you are about to create a name like XXXX’s address book xx-xx-xxxx. Click Save. Click Next. Put check marks in every box in the list, scrolling down the list to ensure you got them all. Click Finish, OK and Close.
Mail: The procedure: Open Outlook Express. Click on Tools, Options, Maintenance, Store Folder. Click your mouse anywhere in the window with the very long list nested folders. Ctrl+A to select the entire contents of the list. If select all does not work, use your mouse to select the entire contents of the box. Ctrl+C to copy it to the clip board. Exit OE. Start, Run, Ctrl+V to paste there from the clipboard. Click OK. That should open the folder that has your mail files. Now you can copy this data into a new folder which you will name on to whatever media you have chosen for your external backup. While you are there, choose the View option Details so you can see the sizes of each file. You should know that OE has an unpublished limitation of 2 GB. When individual files or even the total near that limit, strange things can happen. If they are too big, you need to either delete some or create new folders and move the mail in them to the new ones. Note: if you delete, they go into the delete folder. You cannot let that folder get to big, so you may have to clear out its contents a bit at a time. In WLM, go to File, Export, Messages. Choose Microsoft Live Mail, Next, Browse to the folder where you want to copy and OK.