Contact norton from the two other machines via your account and use Operating system id to have them remove the old machine activation. I believe there is an additional activation fee. Ps try the norton beta 5.0 free download.
I see you use IE6 on the machine. I would suggest you to update to a newer and much more safer browser. If you need IE6 for work, or you would not like to install IE7 or IE8, than you should download Firefox.