Is you computer doing what you don't want it to do? EG; slowing down so much you think it's crashed are for no reason you music goes down and you don't know why? I have one solution for you.
1. First, reset your computer. If you have some like "CPU Overheat", the try this out. Beware: you computer my be set as 'disabled' so it wouldn't do the error display, so just try it anyways.
2. Now, turn your computer off, and unplug ANYTHING plugged into the tower.
3. Take the slides off of the computer.
4.Take the fan off of the CPU aluminum casing, and vacuum all the dust (My computer had a mat full of dust...).
5.While your at it; why don't you vacuum everything in you tower? It's only sense, after all.
6. When you are down vacuuming (or whatever way your dusting with), put it back to its respected position.
All you need to do now is plugging it back in and trying it!