Enable/Disable add-ins

You can enable/disable add-ins in the following way;

Outlook 2003 and previous

1. Tools-> Options-> tab Other-> button Advanced Settings…
2. Press the "Add-In Manager…" or "COM Add-Ins…" button depending on which add-ins you want to enable/disable
3. For some add-ins you’ll need to restart Outlook for changes to take effect.

Outlook 2007

1. Tools-> Trust Center…-> Add-ins
2. At the "Manage" dropdown list at the bottom select which type of add-ins you would like to enable/disable
3. Press "Go…" and make the changes
4. For some add-ins you’ll need to restart Outlook for changes to take effect.

Outlook 2010

1. File-> section Options-> section Add-Ins
2. At the "Manage" dropdown list at the bottom select which type of add-ins you would like to enable/disable
3. Press "Go…" and make the changes
4. For some add-ins you’ll need to restart Outlook for changes to take effect.

Note: See this post if you get an error when trying to disable an add-in.

Managing add-ins in Outlook 2007