How to Recover your Auto-Complete List in Outlook 2010

Recovering a user’s auto-complete list can be done at the same time as their Exchange migration or even if they were previously migrated. 
Before migration (if the user has been migrated previously skip steps 2, 3, and 4 as they will probably have already typed enough email addresses to create the new Exchange auto-complete file and make sure that Outlook is CLOSED before proceeding):

  1. Make a backup copy (copy and paste the file in the same folder) of the user’s current auto-complete list located in the hidden folder: (WinXP) C:\Documents and Settings\”user”\Local Settings\Application Data\Microsoft\Outlook\RoamCache or (Win7) C:\Users\”user”\AppData\Local\Microsoft\Outlook\RoamCache. The auto-complete list file will be called: Stream_Autocomplete_0_abunchoflettersandnumbers.dat. This will typically be a 500+KB size file. The modified date will be the current date if you are in the process of migrating the user or if you are doing this for a user who was previously migrated, the date they were migrated. I.e. the last time they opened Outlook before migration.
  2. Migrate the user as usual.
  3. Once migration is complete, close and reopen Outlook (this is just to ensure that Outlook and Exchange are playing nice together).
  4. Now you need to create a new Exchange auto-complete file by simply sending a few test messages and typing in full and complete email addresses (I.e. don’t use auto-complete or “Check Names”).
  5. Close Outlook (this is very important so that the Exchange auto-complete file will be created).
  6. Return to the RoamCache folder and you should see a new Stream_Autocomplete file with the current date and time. This is the Exchange auto-complete file (it will be a small file size).
  7. Right-click the new Stream_Autocomplete file and select Rename and use CTRL+C to copy the file name. Then change the .dat extension to .bak
  8. Right-click the original Stream_Autocomplete file and select Rename and use CTRL+V to paste the new Exchange auto-complete file name to rename the original file.
  9. Open Outlook and test that the original auto-complete list is working. If the list is still not working – repeat steps 4 through 8. Sometimes the copy and paste has to be done a couple of times to work.


Mon - Fri: 8am to 8pm
204-474-8600 or
Chat Now button with link

Fort Garry
123 Fletcher Argue
Mon - Fri: 8am to 8pm

230 Neil John Maclean Library
Mon - Fri: 8am to 4:30pm

New! Submit requests & check ticket status online at: