I think that both Windows and Dell's trackpad drivers are trying to handle the trackpad device at the same time.
I uninstalled the ETDWare driver thinking that would be best and yes it does temporarily fix the issue by having just one driver handle the trackpad.The windows 10 driver.
But if you're computer is factory image then you'll have Dell Updates. Dell Updates will then see that ETDWare is not installed and it will download and install it again. Making the whole problem start over again.
What I personally did was manually go into the trackpad settings and disable the Windows 10 Device Driver.
Then Dell Updates reinstalled the proprietary ETDWare trackpad driver. So now that is the one that is active and it works way better than the Windows 10 default driver. Much more accurate.
I have detailed instructions on how to do this procedure here
I now think this may not be a driver problem but possibly a windows 10 bug. It seems random. I've been experiencing random unresponsiveness with the touchpad. I've now disabled the Etdware driver for smartpad and have windows 10 default driver enabled.
Guys here is a major update after I first posted the issue here. (Does not have any solution, just a series of events involving Dell)
Machine: Inspiron 15 - 7548 (256 GB SSD, 16 GB RAM)
Did not install WIndows 10, have pre-installed McAfee, Firefox, Adobe PDF Reader (No other software)
I contacted Dell Middle East (My purchase was from Dubai) and after a month long struggle with their horrendous lack of communication and my issue being handled by multiple people, I first got a suggestion from Dell that a technician would visit me with 3 parts (Trackpad, Fan and Screen) and replace them and see if the problem gets solved. I literally fought with them to explain the fact that this will only waste everyone's time and the issue is not with the hardware and these solutions have been tried by many people (some people from this thread have also tried to replace trackpad and even the whole laptop) but failed.
They finally gave me a Document which I could take to the re-seller from where I purchased the laptop and get a replacement. And after all this long drama which took nearly 2 months and hours of phone calls, the retailer now says this model has been discontinued and you cannot get a replacement. I did a Live Chat with Dell US and they said this model has been replaced with 7558.
The occurrence of this issue has significantly, drastically and rather magically reduced somehow in the last two months but I see no scientific logic to it.
Should I update to Windows 10? Does it really solve this?
My laptop does heat up really bad in the left side (around the area where SHIFT and CAPS LOCK keys are located after 15 to 20 minutes of use. Is this normal?
Can anyone please confirm if this model is really discontinued?
P.S.: Dell ***!
I updated to windows 10, thought it had fixed the problem but then it happened again about a month later. Seemed to happen a few times in a row then nothing again, no idea what sets it off, timings are so random. I do feel it's better with windows 10 though, but might just be my imagination. Be aware this laptop has issues updating to windows 10 though (yet another problem!). I updated soon after it came out so they may have fixed it, but basically the laptop went into a restart loop and took me about 5 hours just to get it to start in safe mode so that I could fix it. It was an issue with graphics card drivers - I found a solution online. Oh, and once I fixed that the start menu wouldn't appear either so had to search for a fix for that too! Anyway, I digress, but yeah, if you do update to windows 10 back everything up first and prepare for problems, but I do think it's better than windows 8 so worth it in my opinion. Also my laptop heats up too, but I expected that as my last dell was even worse for it. I just bought myself a £10 cooling pad with fans, it's pretty effective. So many issues with this laptop! Not happy dell.