F keys, or Function keys, have multiple default uses in Windows, including displaying the Help menu with the F1 key and activating the menu bar in the active software application with the F10 key. There are 12 F keys on PC devices. The exact default uses of the F keys in Windows depend on which F key is in use.
Windows users looking to search for a folder, file or name can press the F3 key. Pressing the F3 key by default brings up a search box in the active window. If no windows are available, the file search folder opens up.
Pressing F5 refreshes any active window. The default function of the F4 key displays the address bar in File Explorer; pressing both the Alt key and the F4 key simultaneously closes the active window. The F2 default setting renames the item currently selected by the user.
The F keys have different defaults in software applications. In Microsoft Excel, for example, pressing the F9 key performs all calculations for formulas in all active worksheets. The F8 key's default function in Excel is to turn extend mode on or off. Pressing F7 displays the spelling box in the active worksheet.