What is going on with my laptop?

So yesterday, I was joyfully playing on my laptop, just surfing the web chatting with friends. When suddenly, a window goes unresponsive, I figure, 'Okay, freak occurrence, sometimes windows go unresponsive if you're asking to much' so I go to click out of that window...and my other window becomes unresponsive, so I go to ctr, alt, delete, and my whole computer is now unresponsive...so I wait a few minutes, but I cannot get my computer to respond, so I hold the power button for 5 seconds and turn it off...waiting another few minute I turn it on...it seems all is well...until a few minutes into talking with friends and playing on the internet again it goes unresponsive! This is a reoccurring pattern. What could be going on?