Post by SC Tom Post by J. P. Gilliver (John)
Toshiba Portégé laptop, using Synaptics TouchPad V7.4 driver.
It's normally fine after a reboot, so I don't _think_ it's the
hardware at fault, though it could be - I know little of how they
Sometimes, it changes dynamics - moving very fast, so it's difficult
to aim it, or very slow, so I'm constantly stroking it to get it to
move at all. Often, at those times, the double-tap to click becomes
hard to use, though the actual buttons (switches) below the touchpad
work. Sometimes, though this _may_ only be since I've been plugging in
a mouse, it doesn't work at all, including the buttons not working.
I haven't been able to pin down any specific action on my part that
triggers the deterioration. I haven't changed any of the driver
settings - at least, if I have, I'd have expected them to apply at all
times, not come on at some unspecified time (I was going to say
gradually, but for all I know it might be sudden; I'm mostly a
keyboard person, so it's just that when I go to use the mouse cursor,
I find it zoomy, sluggish, or dead).
I've been plugging in a mouse, which works fine (either direct or via
a hub). I did notice during one boot a popup - disappearing too soon
to catch exactly, but it said something like "alternative pointing
device detected - blah", and I have indeed found that rebooting with
the mouse connected seems to disable the touchpad altogether
immediately, so I unplug the mouse when rebooting.
(Touchpad haters, please do not respond [unless you can help that
is!]. I like both; I find there are things that each is better for;
but, having an external mouse makes a laptop less wieldy, and uses up
one of the only three USB ports [hence the hub]. And, my hands have
"finger memory", such that I often go to the 'pad without thinking.)
You might try uninstalling/re-installing the touchpad driver from
Toshiba. I had a similar problem years ago (Gateway? Dell? I'm not sure
which), that fixed it. I'd use the one from Toshiba rather than any you
"Synaptics' TouchPad device drivers are customized and supported by
notebook manufacturers to meet specific driver requirements for their
individual products. To ensure the appropriate driver for your device,
always use the driver your specific notebook OEM supports.
Installing a generic driver from this website may result in the loss of
OEM-customized functionality and other issues.
Before upgrading to Windows 10, first check with your notebook
manufacturer for compatibility, then use your device's Windows update
function to ensure you get the correct driver for your hardware."
Touchpad drivers are filter drivers.
They look at a coordinate stream to implement
"virtual" features. You can extract "gestures"
from the stream, or implement "virtual buttons"
for a rectangular subset of the active surface.
On some touchpads, physical buttons exist, which
is a lot easier to deal with.
MS HID driver
The trouble begins, when one of those filter drivers
starts binding to *any* HID device. Some of the
packages have an INF with matching PNP values to
make it work properly (touchpad can be RS232 or
USB). But there have been others, where the driver
supplier must have been out of their mind. Microsoft
released one of those one day, in Windows Update.
It had to be pulled. It was breaking input on
computers (no keyboard).
Filter drivers have an "altitude" parameter.
When more than one filter driver is allowed to
sit in a stack, the "altitude" parameter
decides how the items will stack up. I'm not
aware of any practical examples of this on
end-user systems, but I did find a documentation
page one day claiming that's how it works.
When you prepare a filter driver, there's some
registration process where you can acquire
an "altitude" from Microsoft.
Filter drivers include "Upperfilter" and "Lowerfilter",
and care must be taken when the topic comes up.
You should not delete *every* Upperfilter in sight,
because again, you can break the keyboard input.
When an Upperfilter needs maintenance, there's a
certain ClSID associated with it. Most of the
time, the CLSID people are looking for, is the
one for optical drives. And the numbers are
so similar for those, you can easily make one
little typing mistake and delete the wrong one :-)
Don't be in a rush to delete stuff...