I got an interesting query yesterday. How do I convert all the email addresses that Outlook caches into Contacts? A bit of probing revealed that Outlook stores the auto-complete cache distinct from the address book and doesn’t provide an easy way to browse the cache or to convert those entries into Contacts. The auto complete cache is stored in %APPDATA%\Microsoft\Outlook\Outlook.NK2 file.

To import the auto-complete entries into a Contacts folder in Outlook 2007:

1. Run NK2View (download from http://bit.ly/nk2viewer)
2. Select all the entries and Click on "Save Selected Items"
3. In the dialog that pops up, select "Comma delimited text file" in the "Save as type" dropdown.
4. Give a name and save the file. Also, it might be a good idea to run the command "File -> Backup Current NK2 File".
5. Switch to Outlook and do a File->Import and Export.
6. Select the following wizard steps:
   1. Import from another program or file
   2. Comma separated values (Windows)
   3. Provide the file name, and select appropriate duplicates Option
   4. Select the Outlook folder to import to.
   5. Select the map
      1. Select First entry on the list on the left i.e. "Name" and drop it onto "+ Name" on the right
      2. Scroll down in the Right Hand side list till "+ Email" is displayed
      3. Select second entry i.e. email address and drop it onto Email
7. Press Finish and the import process should begin
8. Verify that the contacts have been imported properly