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

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, Outlook 2013 and Outlook 2016

  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 1: See this post if you get the error “The connected state of Office Add-Ins registered in HKEY_LOCAL_MACHINE cannot be changed.”.

Note 2: You certainly do not have all add-ins enabled for Outlook to work properly. Disabling unneeded add-ins can actually speed up Outlook as well. For an overview see: Which Outlook add-ins do I really need?

Managing add-ins in Outlook 2007
Managing add-ins in Outlook 2007