My operating system is Win XP SP3. While I get the above error message, I can open my Address book and send and receive emails normally. The only effect appears to be that my system seems to work at glacial speed and can quickly 'hang' if I've been using OE6. I'm now using MS Essentials security system but this has not caused any problems before with OE6. I believe that uninstalling and re-installing OE6 is possible but very complicated, but unless I can successfully export the existing files and address book, I cannot reasonably use an alternative. Any help gratefully received but the following don't appear to be solutions to my problem:I have read the link http://social.answers.microsoft.com/Forums/en-US/xpnetwork/thread/a8c8cf17-d792-481e-bcca-13b03852a995 by PA Bear MS MVP . I think we'll find that Outlook (2000) is the troublemaker here.1. Open Registry Editor via Start | Run | type or copy/paste REGEDIT | [ENTER]• Do you have this Registry key?... HKEY_CURRENT_USER\Software\Microsoft\WAB\WAB4• If not, STOP; If so, is there a DWORD named UseOutlook (NB: no space) and is its value set to 1 (one)?He has said that if there is no DWORD named UseOutlook (NB: no space) and is its value set to 1 (one)?1 person got this answerI do too