Try updating your Intel IO driver this will allow windows to see your touchpad as a Precision Touchpad and work again through windows all setting/devices/touchpad.

To get this information you need to log on to support, enter your model number and most importantly Enter your Service Tag Number. 

That will open all the hardware information on your Particular notebook, You should download and read your Service Manual there you will find out how to open your notebook All available driver will be found there under download and drivers.

Thanks for your response. As I wrote, when I updated the Intel chipset driver, this *seemed* to fix the problem.

What I'm looking for is a permanent solution. The touchpad has lost functionality before, I have run updates, and it then appeared to be fixed - until sometime later, when it stopped being fixed.

There is no reason for my touchpad to lose functionality in the first place. How can I prevent this from occurring again in the future?

I wasn't referring to the Chip Set drivers, I referred to the Intel IO driver This is a driver that has a lot to do with HID devices and Windows 10, You'll have to dig through all the drivers available to find it. or perhaps your model doesn't use it? I found it when I could not have the touchpad turn off with a mouse connected. Went through 3 or4 Dell Tech's before one had me download and install Dell Command Update 3.0 once installed if found that I needed to update that Intel IO driver and once installed my issue went away never to return. For me, the 3.1 Version only loaded dell update assistant which could not find the issue or have the features of 3.0 where you can choose which drivers I wanted to install and when. Full control of driver installation works for me.

Thanks again, but I already have Dell Update 3.0, which is what I use to check for BIOS updates and such. I also have SupportAssist.

Today, again, my touchpad settings have disappeared. SupportAssist and Dell Update don't detect any drivers to update. I went online and ran the updater there. It said I needed two chipset updates, but when I tried to download them it just stays at 0%. This is very frustrating. It's almost impossible to type on the laptop because when I accidentally hit the touchpad it moves the cursor, which is why I have it disabled when I'm using a mouse, but that setting has disappeared.

I guess I didn't understand what you were telling me to do, but now I think I may have fixed the problem.

I did this:

I poked around in Device Manager and found the Human Interface Devices > I2C HID Device node had an error. (Code 10)

In Device Manager, I opened System Devices > Intel Serial IO I2C Host Controller. I clicked on the Driver tab; the driver was dated sometime in 2017. I clicked the Update Driver button and selected Search automatically for updated driver software. It updated the driver to version 30.100.1816.3, dated 4/19/2018. I then restarted the computer, and the touchpad worked again. (The Human Interface Devices > I2C HID Device node no longer shows an error.)

Like I said, I've rebooted the computer a few times tonight and the touchpad is still working. I'm keeping my fingers crossed. I'm going to keep track of this problem and update this thread in a week or two to report if the fix seems permanent.

Note that when it is working correctly, when you go to Windows Settings > Devices > Touchpad, It says Your PC has a precision touchpad at the top, and there is a long list of touchpad settings. When the touchpad is not working correctly, this message is not at the top, and the only setting displayed is Touchpad sensitivity.

Thanks again for your help. I hope these instructions help others with the same problem.

Yes, glad to help, this Intell IO driver seems to control a lot of different devices and doesn't seem to update with Dell update Assistant.  Somehow it tells windows 10 that you have a precision device.

Well, shoot, that didn't take long.

I turned on my laptop today and the touchpad problem has returned, so at this point I'm stuck. Bummer.

Starting to sound like a hardware issue?

Yes, that's what I'm thinking, too. I'll have to open it up and check the touchpad connection.

Did you ever fix this? I've been having this issue like 6 months at least, and it sounds exactly like what your problem was. I will run updates and the setting will come back for a bit but the next reboot or update will make it go back to the only touchpad sensitivity setting. It's quite annoying