In message , Mayayana
writes:
"J. P. Gilliver (John)" wrote

| No, that's not it. When I get the fault, it's as if a Ctrl or sometimes
| shift key is stuck down - at least that's the best description I can
| give of it. Arrow key presses are registered - but, say, if the cursor
| is in text, it moves by (and sometimes highlights) a word at a time
| rather than a letter. Sometimes the letter keys do nothing, except that
| (say) S brings up the Save dialogue.
|
| Does sound like a faulty keyboard - but the thing that mitigates most
| against that being the cause, is that different things seem to have
| different sensitivities: usually (though not always), if I switch to
| Notepad+, I can type as normal. (Sometimes I even resort to switching to
| Notepad+, typing the text I want, copying it, switching back to [e. g.]
| my news client, and pasting. [The "mouse" - trackpad - works fine.])
| Sometimes switching to Notepad+ and typing a character or two suffices -
| I can switch back to the other application and typing is back. It's a
| weird one!

It might be worth checking for hooks. If a program
needs to be able to get system keyboard messages it
will install a hook -- normally from a DLL. I use one for an
accessibility library I wrote, to provide notification of
keystrokes in an event, so that each key name can be
spoken aloud for blind people.

Imagine an old-style bucket
brigade. The water bucket gets passed along to the
end. It doesn't really matter how many people are in
the line as long as each does their job of passing the
bucket along. A hook allows constant monitoring. It
could be used by malware, anti-virus, or anything that
provides a service needing to monitor mouse and/or
keyboard.

I can only think of two such that I have: AllChars (which allows me to
enter ½, ö, ñ, ±, and so on, via a laptop keyboard with no numeric
pad), and Noisy Keyboard (which gives me feedback). AllChars seemed the
most likely, as that was the most recent thing I'd installed before the
symptoms started. Although that was back on my XP machine. But I tried
turning it off, or even uninstalling it, and still got the behaviour.

Having said that: I just got one of the manifestations of the weirdness
while I was typing the above paragraph, I turned AllChars off (didn't
uninstall it), and I got my typing back! So, more investigation needed.
I've just turned AllChars back on, and I can still type - including
éûμ„ the odd characters AllChars makes it easy to type. Hmm, I'll
have to play more (-:!

I don't know of anyplace to actually check for running
hooks, but you could try stopping various things, including
services that might need a hook, and see what happens.

I did try that before - closing down everything that was running to see
if it "got better" - but the nature of the fault (comes and goes) makes
it _very_ difficult to study.

If the hook library is faulty -- not always passing the
message along -- that could possibly create symptoms
like what you're seeing. The main suspect to my mind
would be malware or anti-malware. (Like cops and robbers,
sometimes it's hard to tell the difference.

(-:

I assume you've tried a different keyboard. I know you
said it's software related, but you never know. Coincidence
can sometimes mislead.

Yes: both an external one and the on-screen one (simulated keyboard you
click on with the mouse [osk.exe]); it was the latter that convinced me
it wasn't hardware!

--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

"I've got this shocking pain right behind the eyes."
"Have you considered amputation?" - Vila & Avon