From Longman Dictionary of Contemporary Englishhelp screenˈhelp screen noun [countable] a screen that appears when you ask for help in using a computer program, showing extra information or advice
Examples from the Corpus
help screen• As with the shaping section, pressing the F1 key at any time will display a help screen.• There is even a help screen showing you how to use the help system.• Each help screen has an index from which you may select a topic. 