Touchpad on my computer not working

I've had this Dell Inspiron 15 Windows 8 for a year and a half now, and when Windows 8.1 updated, all my gestures on the touchpad stopped working. For example

I can't tap the touchpad to click,

I can't use 2 fingers to scroll anymore

I can't use 3 fingers to switch between tabs 

I can't bring the charms by swiping from the right

I can't do the swipe from the left thing I think that switched apps.

What do i do about this? I'm not a computer junkie, so don't get technical if possible, please.