A long time ago we needed a script to remove the Cached Contacts in Microsoft Outlook. After some research we found that these were stored in a NK2 file in the user profile directory. To run the script please close Outlook and create a new batch file (text file with the extension of .bat), or download the file below. Please not this will create a backup of the NK2 file so everything can be reverted.
@ECHO off
TITLE Clear the nickname automatic completion caches in Outlook
CLS
ECHO Clearing the nickname automatic completion caches in OutLook...
ECHO Created by Blake Niemyjski (http://windowscoding.com)
ECHO.
CD %userprofile%\Application Data\Microsoft\Outlook
RENAME *.NK2 *.NK2.BAK
ECHO.
ECHO The operation has now completed.
ECHO.
PAUSE
EXIT
Download is attached to this post.