I'll like to know why my macbook has become so unresponsive?

Question

It has started a time ago, probably since Lion. But with every update in Safari, iTunes and OS X it has become worst. And Aperture, uffff, another story. When this happens the fan goes very fast, it is very rare I can normally hear the fan of the laptop. If I have any other app opened like Mail or iMessage or any other they start crawling. Sometimes when a notification comes, whatever I'm doing freezes! I have tried a lot of things and whatever I do fix the problem for a few days. The only quick fix is to turn off the computer and turn it on again. I'm getting very tired of this. I'm not into Macs for slowness! By the way, I don't have too many apps, documents, etc. I still have more than half of disk space. I'll appreciate any idea, other than throw the laptop away and change to a cheaper DELL, lol.

Answer 1

How much memory (RAM not hard drive) do you have? While 2GB is the OS X 10.7 and 10.8 minimum, 4GB is recommended.
If you look at your Activity Monitor (In Launchpad, under Utilities), under system memory what does it say for page ins/page outs? If page outs are more than 10% to 15% of page ins, then you can use more memory for what you run. The system writes a page of memory to the hard drive when it runs out of physical memory to run programs, and that can take a toll on system performance if it happens too much.