How do I fix an unresponsive touchpad MacBook air?
For a Mac with a non-removable battery, hold down Ctrl + Option + Shift on the keyboard, then press and hold down the Power button for ten seconds. When you're ready, release them and power the MacBook up again. This should reset the SMC and get your trackpad working again.
How do I reset my MacBook air keyboard?
Shut down your MacBook. Reboot, but while the computer is booting press and hold ⌘ + Option + P + R until the gray screen appears. Release the keys after you hear the reboot sound.