For some reason I couldn’t get the normal move autocomplete.dat files to appdata and rename to work. I found this workaround.
There might be an easier way, but this is the way that I was able to get it to work
01. Download nk2edit
02. Open the stream autocomplete files in nk2Edit %LocalAppData%\Microsoft\Outlook\RoamCache\stream_Autocomplete_*
03. Select all with ctrl+A the right click on any of them and hit “Copy with tab delimit”
04. Open a new excel or calc workbook and paste the previous data into it
05. Then you delete the first column. This can be done by hitting the A at the top then the DELETE key.
06. Then you have to highlight all boxes and right click cut
07. Then paste those into column at (or just delete column A and move everything to it)
08. After you cut all of the .dat files and paste them into the .csv
09. Go to calc or excel and save as csv
10. Click file > new nk2
11. Action > Add records from simple csv file.
12. Find the csv file.
13. Make sure everything looks right
14. Save nk2
How to import into outlook
01. Move saved nk2 file to AppData%\Microsoft\Outlook and rename it to the name of the outlook profile
02. Then open the run box win+r then type outlook.exe /importnk2
02. Once opened up autocomplete should be back