Import NK2 files from older versions

of Outlook into Outlook 2010

Moving from an older version of Outlook, to Outlook 2010 or higher? Need to carry along your “nickname”, or NK2 file, that auto fills when you start typing an email address in the TO: field?

Follow these simple steps.

Additional information on the actual location of the nickname file for Outlook 2010 can be found at the end of the article

To import .nk2 files into Outlook 2010, follow these steps:

1. Make sure that the .nk2 file is in the following folder:
   %appdata%\Microsoft\Outlook

   Note The .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.

Note 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.

Additional notes:

The actual file you are looking for is located is: (This used to be your NK2 File)

C:\Users\%username%\AppData\Local\Microsoft\Outlook\RoamCache\Stream_Autocomplete*.dat.

Deleting this file will not clear your Auto-complete list.  As soon as you start Outlook 2010 the file will reappear, along with any bad addresses.  So how does one clear the entire list?

Use one of the methods listed below to reset the Outlook nickname cache for Microsoft Outlook 2010.

Method 1

1. With Outlook 2010 open, click File (BackStage), and then click Options.
2. Click the Mail tab.
3. Under Send Messages, click Empty Auto-Complete List.

Outlook will generate a new nickname cache.

Method 2

1. Click Start, and then click Run.
2. Start Outlook by using the /CleanAutoCompleteCache switch.
   For example: Outlook.exe /CleanAutoCompleteCache
   Note If Outlook is not installed in the default location, you will need to point to the path of Outlook.exe.

A short video created by Microsoft can be viewed here.