as i had my mac over the past 2 years, i filled it up. it got to the point where i only had 12 gbs of memory left. i know it is not good to fill a comp up, but a lot of applications started crashing. i got a 500 gb internal drive thinking this would help, but apps keep crashing, or "not responding". when i "force quit" them and restart them they work but it is annoying to have to keep doing that. is there any way to fix my mac? please help, this is the first problem i've had with anything apple. thanks in advance.