Prior to Outlook 2010 all this information was kept in a NK2 file, typically called Outlook.NK2. Previously you could just copy this file to the corresponding folder on a new machine and it worked almost like magic. With the new upgrade, not so much. It's not a hard process to import the auto-complete data, but there are some additional steps.
- Copy your old *.NK2 file to C:\Users\%username%\AppData\Roaming\Microsoft\Outlook
- Ensure the name matches your current profile name, default is Outlook. (Look in Control Panel > Mail > Show Profiles... to be sure.)
- Now from the Run... prompt enter: outlook.exe /importnk2 and click OK.
- Once imported the NK2 file will have a .old extension, remove that if you wish to run the import again.
All auto-complete data is now kept within an Outlook 2010 mailbox, so no external files will be needed in the future.