administrater account was deleted by virus i need to reset password so i can update security

i have windows vista. .my grandson downloaded a game and a virus added programs and deleted my administrator account . i can still access my computer through guest account (thankfully i made 2 before the virus hit)but my password is limited and i can not update my computer or adobe,etc, or delete my unused programs,it says i must be in administrator account that i can not access,the virus changed my password,can i reset without password reset disc?i can access my administrator account in safe mode,but have limited usage there