I just got a new Dimension 8400 and everytime I boot up I get a request to register for Macafee SecurityCenter. However, whenever I try, I get an error stating that my Dell service tag is invalid.  I don't understand what this means. This is a new computer purchased from Dell, not second hand or used.  I fear that if I call Macafee, they will tell me to call Dell, and vice-versa. Any help out there? Thanks!