If you are using an Asus notebook/netbook you might have come in touch with Asus Smart Gesture.
This piece of software is responsible for the proper function of your touchpad.
Unfortunately it happens, that when your device is going into hibernate/sleep mode and you wake it up again, the gestures won’t work anymore.
There’re a lot of advices out there. From reinstalling ATK and/or Asus Smart Gesture software to creatig some batch files – some might work, some won’t.
What worked for me was disabling the energy saving option of the AsusVTouch device using the device manager.
Press WinKey+X, choose device manager, go to Input Device (not mouse/mice!!), right click the AsusVTouch entry and choose Properties, switch to Energy and remove the checkmark from the box.