Importing NK2 addresses into Outlook 2010 suggested contacts

Posted on September 1, 2010

In previous versions of Microsoft Outlook (2003 and 2007) the nickname cache was stored to a NK2 file locally on the client's pc. This is hands down one of the most used features for pretty much anyone using Outlook. Let's face it, it's quick, simple and does what it should.

You can find the NK2 files here:

  • Windows XP
    Drive:\Documents and Settings\Username\Application Data\Microsoft\Outlook
  • Windows Vista and later versions

With the release of Outlook 2010, the NK2 file has been retired and replaced with "suggested contacts".  Of course with user relying on their existing nickname cache so heavily, you don't want to lose the data. The following method will assist you by importing an existing NK2 file from previous version into Outlook 2010.

  1. Make sure that the .nk2 file is in the applicable folder listed above.
    NoteThe .nk2 file must have the same name as your current Outlook 2010 profile. By default, the profile name is "Outlook." To check the profile name, follow these steps:

    1. Click Start, and then click Control Panel.
    2. Double-click Mail.
    3. In the Mail Setup dialog box, click Show Profiles.
  2. Click Start, and then click Run.
  3. In the Open box, type outlook.exe /importnk2, and then click OK. This should import the .nk2 file into the Outlook 2010 profile.Note After you import the .nk2 file, the contents of the file are merged into the existing nickname cache that is currently stored in your mailbox.
    The .nk2 file is renamed with a .old file name extension on the first start of Outlook 2010. Therefore, if you try to re-import the .nk2 file, remove the .old file name extension.