Collect Http 404 error from the running users

[Andrew2]

Hi all, and happy new year

I'm facing with a problem. I need to know if an IIS page for 404 error
has been configured. Originally I tough to querying LDAP/ADSI using
new DirectoryEntry("IIS://localhost/W3SVC"), but Network service user
hasn't the right to access to that kind of information.
Apparently it seems that only administrator has the right access. Is
there any other way to get that error page?

Thanks
Andrea