I have assumed that:
1. Your identity is based upon an email account @hotmail.com,
or @msn.com, or @live.com - and
2. When you open WLMail, you allow it to sign into the same
hotmail, msn or live identity
If these assumptions are correct, an easy way to clean your
contact list is via the webmail interface.
Close Windows Live Mail
Use your web browser to sign into your mail account at http://mail.live.com
Click on Options, followed by More Options.
Scroll down to "Customize your contacts", and click on "Clean up
Use the wizard to merge or delete duplicates.
Sign out from the webmail interface
Open Windows Live Mail and allow the program to sign into your
When you select the contacts menu, WLMail should synchronize with
the contacts list on the central server.