I saw one thread on this but let me explain my situation: I uninstalled Outlook 2007 and downloaded the beta of Outlook 2010. Autocomplete worked for some time then stopped. Last week I uninstalled the beta and downloaded the full version. Autocomplete still does not work. I deleted the 2 profiles I have (I run two domains) and set up two new one. No luck. THis is beyond frustrating and I need HELP!!!