ISKB:How to add CRM buttons to Outlook
From Test wiki
If you're CRM buttons are not present, you will first need to go to Start -> control Panel -> Run Advertised Programs and choose "outlook CRM" from the list. This will install the prequisites.
Next go to http://crm/outlookaddin/outlookcrm.vsto in IE to install the actaul plugin. It's a good idea to have Outlook closed while you do this. Once the install has finished, open Outlook and your CRM buttons should be there.