The only thing i can suggest is to uninstall/reinstall prog and try again and maybe email kaspersky again, I know its not much help really but its the only advice i can give you in relation to activation codes, the posting of which is prohibited by the rules of the forum..
You haven't actually registered for the Kaspersky software yet. You need to click here, answer the question and then click on 'Register for Software'. The next page will provide your unique code, and this will also be emailed to you. I think you must be trying to use the 'authorisation code' which was sent to you when you initially registered for the PC Advisor website - this won't work for Kaspersky, you need to go to the special registration page we've set up to get your code.
Please contact me directly using the yellow envelope next to my user name if you have any more difficulties.