How can duplicate files be removed?

When I thought I had lost my imported Outlook data, I imported it again. Then my Contacts showed up with each entry duplicated. Is there a way to remove the duplicates without deleting each one?

Hold Ctrl and select each of the duplicate entries to delete them. You shouldn’t having any problems on doing so.

TNCS: If that’s the best I can do, OK. I was hoping for a duplicate-removing tool or some such.
Thanks for your reply.