While backing up your emails messages you must remember to do the same with the Address Book where you have all your contacts.
Here few easy steps to do the job:

1. Open Outlook Express
2. Click on File > Export > Address Book




3. On the next window click on Text File (Comma Separated Values)




4. On the next window Browse  your HD to the location where you want to back up the Address Book and give it a friendly name (My_Address_Book)for example and click next




5. On the next one you can select which field you want to save,such a contact specific detail.To select one, tick on the square box next to the detail you want to export,to unselect just remove the tick by simply clicking on it




6. Click finish and , if successful ,you'll get a message like the following

How to  Import the Address Book

Now , if you have already successfully backed up your Address Book and you want to restore it or transfer it to another computer whether new or only different,follow these steps:

1. Open Outlook Express
2. Click on File > Import >Other Address Book





3. The Import Address Book Wizard opens,select Text File (Comma Separated Value)
4. Click Import





5. Browse to the folder where you previously saved  the Address Book file.It should have an extension like MyAddressBook.csv
6. Select the file and click Open at the bottom of the window,you are returned to the previous window,click Next





7. On this window you can select or deselect the contact details you want to import.You can also change the mapping,for example if you want the contactHome Phone to be the work Phone.When you ready click Finish





8. After a while,depending on how big the Address Book is,you are prompted with the message " Address Book Import Process Has completed" Click OK
9. You will be returned to the first page of the Import wizard,if you don't have any other address book to import click on Close
10. Now click on Tools > Address Book and you should be able to see your new Address Book