UAC when changing system settings. What could be the reason?

Question

System administration

Actually I'm trying to connect a PC with Win7Prox64 to the AD domain
System properties -> Change settings -> strange UAC

has never met before, what could be the matter? virus? damaged system?

Answer 1

in fact, everything turned out to be simpler and more tragic.
the "admin" account from which the manipulation was performed was not included in the "Administrators" group on the local machine. like this.
inattention kills time - the most important, most valuable resource.
thanks to all :)

Answer 2

What account are you using?
If under the domain administrator - there were no questions.
Under the user never tried.