can't plan a scheduled scan

Hi, I have windows vista and norton 2009, everything is installed, but when I try to plan a complete system scan, I get an error. I don't know if it's a norton error or a windows error, but when I try to schedule a scan and save it, it asks for my login name and password. I'm the account manager for my windows vista and don't use a password on it, cause I'm the only one using my computer, and I already tryed the loginname and password for norton, can somebody please help me?

 

(by the way, if I'm making any errors in my typing, it's cause I'm dutch, not english, but I'm trying:smileywink:)