Left click not working

Hi all,

I have an Air less then a year old. I was using it fine this morning but when I went to use it later today I found I couldnt use the left click on the track pad. I tried a USB mouse and that isnt working either. The mouse still moves around the screen and right click still works on the USB mouse. Obviously I have tried resetting.

I managed to get to System Preferences and Track Pad and noticed that none of the boxes under One Finger Tap were checked. Without the mouse I cannot check them.

Can anyone help me out? Is there a way to reinstall the drivers or do a reset or something?

Thanks

Um so after 10 resets and messing around I gave up and left it for half an hour. And now it works again...I cant explain this