Unfortunately, Google Search has stopped..?

I've been using the tablet ALL day, and now every time I try to type something anywhere a dark gray box pops up saying "Unfortunately, Goggle Search has stopped."

It is really getting on my nerves and I can't go on anything at all! -.-

Also, the WiFi went down so I can't even play the games I installed earlier... ;-;

How do I get rid of this thingy...?

Or... How do I get Google Search to work again??