My Windows Live Messenger contact list was empty for 2 days. After restart PC still the same. Finally this trick help me fix it.
1. Exit Messenger
2. Go to Run and enter
Windows 7
%LOCALAPPDATA%\Microsoft\Windows Live\Contacts
Windows XP
%userprofile%\Local Settings\Application Data\Microsoft\Windows Live\Contacts
2. Delete folder name with your HOTMAIL email address
3. Launch Messenger and Hooray ! Your contact is BACK !
