how many keys are on microsoft windows standard keyboard
Computer keyboard Standard alphanumeric keyboards have keys that are on three-quarter inch centers (0.750 inches, 19.05 mm)[citation needed], and have a key travel of at least 0.150 inches (3.81 mm). Desktop computer keyboards, such as the 101-key US traditional keyboards or the 104-key Windows keyboards, include alphabetic characters, punctuation symbols, numbers and a variety of function keys. The internationally common 102/104 key keyboards have a smaller left shift key and an additional key with some more symbols between that and the letter to its right (usually Z or Y). Also the enter key is usually shaped differently. Computer keyboards are similar to electric-typewriter keyboards but contain additional keys, such as the command or Windows keys. There is no standard computer keyboard, although many manufacturers imitate the keyboard of PCs. There are actually three different PC keyboards: the original PC keyboard with 84 keys, the AT keyboard also with 84 keys and the enhanced keyboard with 101 keys. The three differ somewhat in the placement of function keys, the control keys, the return key, and the shift key.
Keyboard layout Instead of the Alt and AltGr keys, Apple Keyboards have ⌘ Cmd (command) and ⌥ Option keys. The ⌥ Option key is used much like the AltGr, and the ⌘ Cmd key like the Ctrl on IBM PCs, to access menu options and shortcuts. Macs have a Ctrl key for compatibility with programs that expect a more traditional keyboard layout. It is especially useful when using a terminal, X11 (a Unix environment included with OS X as an install option) or MS Windows. The key can generally be used to produce a secondary mouse click as well. There is also a Fn key on modern Mac keyboards, which is used for switching between use of the F1, F2, etc. keys either as function keys or for other functions like media control, accessing dashboard widgets, controlling the volume, or handling exposé. Fn key can be also found on many IBM PC laptops, where it serves a similar purpose.