wallpaper and screensaver problem

[ferds]

hi..I have a problem with my new window 7 laptop regarding how to change my wallpaper and screensaver..I can't change it..when I go in to Personalize then when i click the screensaver or wallpaper setting theres a note coming up saying.
    ''Application attempted to perform an operation not allowed by the security policy, to grant this application the required permission, contact your system administrator use the microsoft.NET Framework configuration tool.''
 I try to locate the administrator config but i don't know where to change it..my wall paper And screensaver is not working properly.how can i change back to normal?

[Salmon Trout]

When you say this is "your" laptop, did you mean it is your property or is it owned by someone else such as your parents, employer or school?

[ferds]

yes this is mine..