I’ve played enough games that I think I’ve used all the keys on a normal computer except maybe the scroll lock. On my current work keyboard, however, there’s a key between the right Windows key and the Ctrl key that has an icon for it which is a rectangle with three lines in it. I don’t even know what it does.
I use Pause/Break daily: WinKey+Pause opens the System menu, and from there it’s one click to
Device Manager.
Scroll lock gets very little use ever since the DOS days. Of the F keys, F1, F5 (refresh and quicksave in many games), and F8 (quickload) get the most use. I don’t use F11 or F12 much but I can see why people do. I use them mostly to cancel the mode when a cat sits on them. Same with F7, which starts caret browsing, a feature I didn’t even know existed before the cats figured it out.
Home/End/PgUp*/PgDown I use daily, and I find laptops that don’t make them easy to use semi-worthless.
*Pig Up. It’s on the keyboard along with catarol and esk.
It brings up whatever is the current-context menu.
Which usually means the same thing as right-click.
The “~” symbol got a bit of a workout on the debate over whether 0.999~ = 1.0
Those are my “go to” keys when doing search-and-replace that I want to undo again later.
Useful when doing big spreadsheets: it shoots you right back to the leftmost column.
But, yeah, there are rather a few keys I’ve never used! (Some, I’ve hit accidentally, like the Windows key and cAPS lOCK. Phooey!)
The one at lower left that has a 4-panel wavy flag all inside a circle. What’s that?
I’ve used all of them, but scroll lock is probably the least used. I use it occasionally in Excel.
The wavy flag is the Windows key. It works much like the command key in Mac (which used to also have open-apple and closed-apple keys.) It can also open the Start menu and be used in a number of useful shortcut commands. If dual-booting (or virtualizing) Windows on Mac hardware, the command key is the Windows key.
Scroll lock is a pretty good example of a key which has lost its initial purpose in existence, and most of the alternate uses are obscure or not that useful.
Scroll lock was to pause the flow of information on a screen of alphanumeric stuff scrolling by. In the GUI era, that’s mostly mythical. How many users of Windows or MacOS even know what a command-line console is, let alone any command that you’d use there?
Those who do, such as me, came up in environments which had lots of text scrolling by on-screen, but before the “scroll lock” key appeared on a keyboard. For that, we’d use “control-S” and “control-Q” to pause and resume scrolling.
DOS allowed you to pause scrolling data by typing anything, and resume by backspacing out what you typed, so “space bar” and “backspace” are pretty convenient. Much more physically convenient than a small key in an obscure corner of the keyboard, right next to the button that would dump the contents of the screen to your printer if you accidentally hit it (“Print Scrn” – that’s what it was for!).
The only other thing that Scroll Lock is “useful” for is in Excel, where it changes the scrolling behavior of the arrow keys. Instead of moving your “cell selection” cursor, (i.e., selects the next cell over in the direction of the arrow movement), it moves the window of cells displayed on-screen without moving the cell selection. That has never been useful to me in my 15 years of nearly-daily interaction with Excel, and I have no idea what problem that was invented to solve. 
I’ve used all of the keys at least once. I seldom use the “clear” key, and I probably don’t use the right Command, Option, or Control Keys too often. Oh, and Caps Lock – I have that disabled in Preferences.
Which is the clear key? And…how do you disable Caps Lock?
(I did some searching, and see that you can do scary things with Registry entries. Not me! That’s too much like doing my own surgery.)
Only the Pause/Break key for me at the moment (Although I have definitely used it back in my DOS days)
OT:
If you take the time to learn all the keyboard short-cuts in Word/Excel (for example) you’d be surprised at how much quicker it is to work on documents. Moving your hand from keyboard to mouse and back again is such a time waster for some applications. For those that worked on old text-based systems, you’d recall how quickly you could move between screens/fields once you’d memorized the key presses.
For a good start in Word:
- F4 - repeat the last edit
- CTRL+(Shift)+L&R Arrows/Delete/Backspace - Move across a line, highlight and delete whole words at a time.
- CTRIL+(Shift)+ Up or Down Arrow - Move between and highlight whole paragraphs
CTRL+Shift+C/V - Format Painter Copy/Paste. (Format painter being probably the best tool in the Office suite IMHO)
I pried my Insert key out with a screwdriver several years ago, pour encourager les autres.
For the record, and I should have mentioned this in the OP but I forget they’d be different, I live in the UK so my tilde is down by the right shift. My “left of the 1” is ` ¬ and ¦, and as far as I can recall that’s the first time I’ve pressed it.
Okay, I’ve never used ¬ and forgot that it even existed on other keyboards. The ¦ is on US keyboards (though ours is solid: |) and shares a key with \
The | / ¦ is usually called the pipe, and I used it in DOS days but not so much today. I still would use it for stylistic reasons though.
And the ~ / ` key, besides being used for inequality sometimes, is used in many games to access the console.
Isn’t Command (⌘) more analogous to Windows Ctrl? Though in different locations, both are the most ubiquitous modifier, and used in the same commands (e.g. copy is Ctrl+C or ⌘+C). Whereas the Mac Control key mostly is used in combination with Command and/or Option/Alt, and less often by itself.
I do see that Wikipedia agrees with you that Command and WinKey are equivalent, but from a utility standpoint I’m not sure that’s true. The WinKey did become more useful staring with Win7.
On this keyboard, save for originally testing some of them to see what they do…Ins, Pause/Break, and FN (which I think is supposed to be a sort of shift key for the F keys, but none of the functions those are supposed to activate work)…hmm…probably some of the F keys, but games do use them a bunch, and I use F1, F2, and F5 a lot, even outside games, and F12 while playing games in Steam. (Help, rename, refresh, respectively, and Steam’s screencap key.)
I did use Ins and Pause/Break a lot on my ooooold DOS box back in the days of dinosaurs.
Fn is really only seen on laptops or keyboards with fewer keys and does the secondary or tertiary functions of each key. For example, some laptops put Home/End/PgUp/PgDown on the arrow keys, requiring two fingers to use these functions (one of those keyboards that I hate). The F keys usually have brightness adjustments, volume, etc. on them. Depending on how you’re set up, pushing without Fn may default to either the F key or the secondary function, or vice versa on other setups.
It’s embarrassing how many keys I do not use. I never touch any of the Fn keys(*). I never use the number pad — except to type dashes — — that’s the only Alt-code I’ve memorized. I went for decades without ever clicking CapsLock deliberately(**), but just a moment ago someone started SCREAMING at me on another message-board so I SCREAMED back. I’m more fluent in C than I am in English, so {}^&| etc. get a good workout.
Thirty-five years ago, I read the hype about IBM PC and how key meanings could be customized, wrote a very nifty application which treated Ins- and Del-keys symmetrically … but discovered the auto-repeat for the former was disabled in the Bios ROM! :smack: This irritated me so much that for 35 years I’ve never pressed either of those keys deliberately except the latter in concert with Ctrl and Alt.
My mouse has about 7 buttons only three of which I use. Sometimes a 4th button gets pressed when I bump the mouse into something. This has unpleasant but, so far, not disastrous results.
Sometimes I press the Shift key several times mindlessly (No effect, right? And better than biting my fingernails, right?) I discover that leads to a Microsoft query, asking if I want help!
(* Actually there’s one Fn key that, once or twice a year I need to push 4 times or such when my Wifi glitches out 
— I usually let my son do that for me.)
(** - We are talking about deliberate presses, right? My fat fingers often press the wrong button by accident. Fortunately the results are seldom disastrous.)
The “Clear” key is (on a Mac) where the “Insert” key is on a DOS keyboard. You’ll need a Mac to disable the “Caps Lock” key in System Preferences, though!
It’s not too bad. Microsoft and application vendors bury a lot of useful functionality in the Registry. It’s really just a big list of preferences and defaults.
Japanese laptop with Japanese keys, and a Chinese language kit added as well. There are a few keys were are only used when inputting in the kana mode. Don’t use them or some of the f-keys and the PAUSE/BREAK key.
Now that I’m not using spreadsheets and editing documents there would be a number of keys which I would be less likely to use on full keyboards.