My Escape key randomly stops working.?

I have a Sony Vaio laptop which ive had for a few months now and just recently mt escape key stops working. So praying it isnt a hardware problem and restarted my computer. And the problem went away. But it reappears randomly. So my ysis is that its a software problem but i dont know which one makes this happen. Any clues as to what makes it do this? its very annoying when playing a game and not being able to exit out of it or exit a fullscreen video. thanks.