Remove it. Method depends on your Outlook version, which you did not post.
For Outlook 2002:
Go to Tools > E-mail accounts > View or change existing directories or
address books > Outlook Address Book > Change. >

Signature
Russ Valentine
[MVP-Outlook]
> When i click the to button I see contacts listed under show names from the:
> but there are no contacts in the list area. The down arrow in show names
> will show another 'contacts' and when clicked will display all the names
> inthe list area. How do i get rid of the contacts that shows nothing?