I installed Windows 10 almost 10 months ago and had problems with the cursor behaving crazy almost all the time, staggering, moving slowly, stopping and the unit became unusable. I completely reimaged it with a full HD wipe after dealing with the windows 10 team at MS unsuccessfully for over 2 weeks. Problem came back in Windows 7 after all that. I tried many drivers on the touchpad and even installed a new one but the problem continued. I found when a mouse was installed I could use it so I did for many months.. thinking maybe there was a motherboard issue. I finally determined the problem was related to Firefox. With Firefox uninstalled for 2 month now, it works perfectly on IE 11, which I hate. I like Firefox much better but I need a absolute solution to the problem before I install it. My laptop is a Dell E6420 Latitude. If I can get Firefox working correctly for a few months on Windows 7, I would put in Windows 10, but I must be sure.. This is a huge issue that caused me so much time and trouble that Firefox owes me big time, thanks, Bob