I am using Outlook 2000 with XP SP3 on my workstation. I have Outlook 2000 installed on other machines and it runs much faster. After reading old threads, I started Outlook in safe mode and it ran much faster. It seems to only be slow when there is a window open like when I double click to read an entire email. I found my extend.dat file and renamed it and restarted Outlook without any real speed improvements. I seem to have tracked it down to when I use the preview pane to view emails. When I turn that off, it seems to speed things up especially when navigating away from an open Outlook window to another program. I really like the preview pane. Is there any way to keep this option and still speed up my outlook? Thanks.