Left mouse click quit working

Hi

If this a laptop touchpad mouse button, I've had a similiar problem with a older laptop, the button was not getting touched properly, I had to press it harder a few times and it eventually started to work again.

There maybe something in between case and the button that is perventing it from being pressed completely.

If this doesn't help, try using a external usb mouse for example.
The laptop might need to be taken apart and the touchpad buttons looked at and possibly cleaned or the buttons / whole touchpad replaced to sort out the problem.

Thanks and good luck, let me know if you need further assistance.
Ekse