‘Error in registry for extension “Exchange Extensions;?”‘ error message when you start Outlook 2003

This error occured when working on a problem for a client where a third party fuel monitoring system was being linked up to email to send status reports. The system had been working successfully for a period of time and then developed the habit of popping up the message (5 times) before allowing the user into the application. Given the scheduled nature of the emails it became apparent that the message was only displayed after the jobs had run and not at other times. It was also displayed when starting Outlook 2003 independent of the other application.

The only other factor in this problem was that all of this was happening in an rdp session on a remote machine. The error did not appear for a similarly configured  outlook account in another rdp session. The initial approach was to look at the addins that were being loaded – interestingly there were 5 of those. Disabling these unfortunately had no effect.

A Microsoft KB article here suggested removing a registry key but on checking the key in question did not exist on the remote machine.

Soution: In the end – giving permissions on the parent registry key above the one mentioned i.e


to the user logging into the rdp session with the problem stopped the error message and allowed outlook to run successfully both starting itself and being activated by the third party application