Hi Midge,

You want to find duplicate or unique contacts but didn't mention what type of contacts such as email address, Phone no., pictures etc & which platform Outlook or windows so it will be great if you can give more details. Suppose you are talking about Outlook than you can create a distribution list to manage contacts. Here is the link which is really helpful as troubleshooting http://office.microsoft.com/en-us/ou...010205427.aspx

Thanks !