How to Back up or Copy Your Outlook Auto-Complete List

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You can export the list Outlook maintains to auto-complete addresses as you type them in To:, Cc: and Bcc: fields.

Where Outlook Keeps Auto-Complete Information

Outlook keeps most of your essential data in your PST—personal folders—file. The auto-complete list Outlook pops up when you start typing somebody's name or address in a new message is just as essential, though, is it not?

This list (which you can really edit only with a dedicated tool) is, as it were, stored in a separate file (called NK2 file) with Outlook 2003 and 2007; with Outlook 2010 and later, the same information is stored in a hidden message in your default email account.

If you want to take the auto-complete list with you to a new computer or want to make sure it is backed up regularly, you have to dig it up from within Windows' profile directories or from deep within your message store. Either is entirely feasible, however.

Back Up or Copy Your Outlook Auto-Complete List

To export a copy of the Outlook auto-complete list—for backing it up or to copy the list to a different Outlook installation:

  1. Download MFCMAPI.
  2. Extract the downloaded .zip file.
  3. Make sure Outlook is not running.
  4. Double-click mfcmapi.exe to launch it.
  5. Select Session | Logon… from the menu in MFCMAPI.
  6. Choose the desired profile—typically Outlook—under Profile Name:.
  7. Click OK.
  8. Double-click your Outlook email profile in the Display Name column.
  9. Expand Root in the viewer that appears.
  10. Expand IPM_SUBTREE (or Top of Information Store or Top of Outlook data file).
  11. Click with the right mouse button on Inbox in the list that has appeared.
  1. Select Open associated contents table from the context menu.
  2. Click on IPM.Configuration.Autocomplete in the Subject column with the right mouse button.
  3. Select Export Message from the menu that has appeared.
  4. Make sure MSG file (Unicode) is selected under Format to save message.
  5. Click OK.
  6. Open the folder to which you want to export the Outlook auto-complete list under Save in:.
  1. Click Save.
  2. Close the dialogs and quit MFCMAPI.

Back up or Copy Your Outlook 2003 and Outlook 2007 Auto-Complete List

To transfer your Outlook address auto-complete list or create a backup copy:

  1. Close Outlook.
  2. Open Windows Explorer.
  3. Click in the address list.
  4. Type "%appdata%\Microsoft\Outlook" (not including the quotation marks).
  5. Hit Enter.
  6. Click with the right mouse button on the Outlook.nk2 file.
    • The file can also be named after your Outlook profile, e.g. Ina Cognita.nk2. Make sure the extension is nk2.
  7. Select Copy from the menu.
  8. Go to folder or medium where you want to keep the backup copy, or open the "%appdata%\Microsoft\Outlook" folder on the destination computer directly.
  9. Make sure the copied NK2 file replaces the original default NK2 file. Either rename to match the profile name or overwrite at pasting.

(Updated April 2016, tested with Outlook 2007 and Outlook 2016)