The auto completion of Microsoft outlook is working with the help of a file with .NK2 extension. It is an auto generated file according to user activity. Sometimes you may need to edit the file to remove unwanted contacts from the auto completion list. There are no explorers like address book for this file. There [...]

. The location of the NK2 file created by Outlook might be different from one computer to another, depending on the operating system and the version of Outlook.  Refer following path to fond the file