Windows Dev Center states:
"Dialog boxes always have a Close button...Don't disable the Close button. Having a Close button helps users stay in control by allowing them to close windows they don't want."
However, they do show an example of a dialog with no close button. They provide a few scenarios (e.g., loss of data, progress, etc.) to justify this pattern.
I can only think of one other acceptable use of this pattern:
- When someone has preformed an action (e.g., changing important system setting, etc.) that may have an unintended consequences. As a result, requiring users to confirm/pick an option. I'm opposed to confirming any user action but maybe it's OK if it stops people from ruining their computer. Raising the question: why give people that option? (That's for another thread...)
- Are there other scenarios that justify removing the close button?
- Have you seen any examples "in the wild"?