Using the action keys
An action key performs an assigned function. The icon on each of the f1 through f4 keys, the f5 key (select models only), and the f6 through f12 keys illustrates the assigned function for that key.
To use an action key function, press and hold the key.
The action key feature is enabled at the factory. You can disable this feature in Setup Utility (BIOS).
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To activate the assigned function after you have disabled the action key feature, you must press the fn key in combination with the appropriate action key.
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(p. 37 din manual h10032.www1.hp.com/ctg/Manual/c03837811.pdf )