missing buttons on ctrl + alt + delete window

[Nick]

when doing a ctrl + alt + delete, the window that pops up is somehow missing
the close, minimize and maximize buttons. rebooting does not get rid of it.

any idea how i can either close it or get the buttons back on it?

 

[Doug Knox MS-MVP]

Double click anywhere on the blank border.

 

[Mathiau]

double click anywhere on it.