Officially, Dell only supports EXX30 series and newer. But a lot of times, W7 drivers do work in W10. I would go to Dell's website and pull the touchpad driver for W7 and see if it works.

Dell Latitude E6420 Driver List for Windows 7 January 13, 2012 Whenever I get a new computer, the first thing I do is format the hard drive to remove all the manufacturer bloatware and then install the operating system of my choice. In this case, I chose Windows 7 Professional x64 and I found all the drivers you need to get rid of those yellow exclamation marks in the Device Manager for the E6420. Delphi serialize xml.

Dell does a very nice job of organizing the downloads based on laptop model, operating system, and category, but they don’t tell you which ones you actually need. If you just installed Windows 7 x64 on a Dell Latitude E6420, these are devices missing drivers in Device Manager (Start -> Type in: devmgmt.msc): Broadcom USH Ethernet Controller Intel Centrino Advanced-N + WiMAX 6250 Mass Storage Controller Network Controller PCI Serial Port PCI Simple Communications Controller SM Bus Controller Unknown Device This list is probably very close to yours depending if you bought the WiMAX card or other options.