Missing driver on install of MP

This morning I deleted Mission Planner from windows 10, and tried to reinstall it because I was having problems - screen lockup when setting up accelerometer. I was unable to reload the drivers-- the second driver in the list, “usb…” is Xed out- does not install. (W10 tells you d----d little about drivers, even the full name, it seems.) The rest are ok.
MP ran fine before today in 10, and installed all the listed drivers
Any ideas, anyone?