Configuration - Pentium Quad core N3540 + 4GB DDR3 RAM + 500GB HDD + 1v3 & 2v2 USB ports + Wifi + HDMI No DVD drive or Ethernet port
After updating to the latest available BIOS ver A02, the Intel serial I/O driver fails to install or operate correctly.
I observed that with A02 BIOS, Intel serial I/O driver did not install when setting up Windows 10. Perhaps the Touchpad operation is related to this driver because even though the Touchpad driver installs OK, only basic functionality is available. Advanced Touchpad features like multi-touch, gestures etc are disabled.
Also after updating BIOS to A02, Touchpad stopped working in Windows 8.1 installed on a different partition.
After flashing the older BIOS version A00 file, the Intel serial I/O driver installs properly in Win10 and Touchpad function has returned to normal.
Please check BIOS version A02 for possible bugs.
I had exactly the same problem. I bought Dell Inspiron 15 (3551) with Windows 10, I installed all the drivers, etc. and then decided to upgrade BIOS.
After the upgrade, the Synaptics driver stopped working (no multi-touch gestures). I even couldn't uninstall it.
Then, I re-installed Windows 10 and checked for updates. Synaptics driver wasn't found. So I downgraded by BIOS firmware and Windows Update instantly found the touchpad driver and now everything works fine.
If would be great if Dell fixed this.
Thank you for validating this problem. The BIOS of Dell 15 3551 has a bigger problem - It is TOTALLY incompatible with Windows 7. It won't even install due to Non-ACPI compliant BIOS.
I even tried to create custom Windows 7 install media and tried everything I could find.
I am still not comfortable with Windows 10 due to constant updates which might make system unstable anytime. But can't go to Win 7 due to BIOS.
Asus & Lenovo BIOS'es provide options to switch compatibility between Windows 7, 8, 10 but Dell is in DEEP SLEEP. They are not even acknowledging the problems let alone provide solutions.