McAfee / MS Outlook Add-in Problem

My new Dell Inspiron 530 with the Windows Vista Home Premium operating system and MS Office, Small Business Edition, arrived last week. The second or third time that I started the machine and launched Outlook, I received a horrible message about a conflict with an Add-in that prevented Outlook from opening. I responded “Yes” to the question in the error message, permanently (?) disabling this Add-in. Outlook now runs fine. But when I open Outlook’s Trust Center and go to the Add-in section, I see that the McAfee Outlook Add-in appears under the Disabled section. So now I’m worried that my new machine is not protected by McAfee’s Virus Scan. If I highlight the McAfee Outlook Add-in line and click Go, I bring up the list of all Add-ins available with check boxes adjacent. But if I try to click the blank check box adjacent to McAfee, I receive a very bizarre error message: “The connected state of Office Add-ins registered in HKEY_LOCAL_MACHINE cannot be changed.” What does this mean? Have I permanently lost McAfee’s Add-in for Outlook? Am I protected?