Defragmenting your whole computer may also help. If you do that regulary (by installing BoostSpeed for example or use Windows own defragmentation program if you have Windows) your computer will work faster, more efficience and it is more stable.
If you don't know what defragmenting is than you can compare your computer with a library. Whenever you need information you can take a book out of a book cage to read it. But sometimes books are put back in the wrong order. They're still there, but it is harder to find them again. And if you need to relocate different books at the same time you could end up feeling stresssed.
And that is what happens to your computer as well, from time to time. They become slower. They won't stress, but they do crash.
Defragmenting your computer will litterly put all books back to where they belong, so your computer can find the information faster.